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THE STORY OF COPPER 


SYMBOLS OF AMERICAN FREEDOM 


The Bronze Liberty Bell that announced the Declaration of Independence and the 
copper Goddess of Liberty, the colossal statue that guards New York Harbor. 


FIRST AMERICANS MINING COPPER y 
This United States 


National Museum group portrays a warrior, with amulet of hammered copper, com- 
pleting the extraction of native copper which has been exposed by action of fire and 
A copper knife-blade is being sharpened by blows from the other Indian’s 


flint mallet. 


Indians were the first copper users on the American continent. 


water. 


THE STORY OF COPPER 


BY 
WATSON DAVIS, C. E. 


MANAGING EDITOR, SCIENCE SERVICE 


ILLUSTRATED WITH 
PHOTOGRAPHS AND DIAGRAMS 


‘TINTON-NEW BEDFORD COPPER COM ANY 
WRECKS OF 


THE CENTURY CO. 
New York and London 


x 


To 
Tue Man Who First Usep Copper 
AND 
Tue Mittions Wuo Have Improvep Upon 
His Discovery 


Tuis VoLuMmE 1s DEDICATED 


9Y9SGOS8O 


ae 


FOREWORD 


Telling the story of a metal so old and yet so modern 
in its applications has been a fascinating task. My 
hope is that the printed page will carry over to the 
reader some of the enduring romance of copper and 
that every copper-containing object that comes within 
his view will have a new background. 

Necessarily there is little in the following pages that 
is not more fully told in some frankly technical book. 
The bulk of the material presented is, like the proc- 
esses and uses that are described, the common herit- 
age of mankind. As Herbert Hoover says in an in- 
troduction to one of his books: ‘‘If any may think 
that there is insufficient reference to previous writers 
let him endeavor to find to whom the origin of our 
methods should be credited.’’ I have, however, at- 
tempted to include in the reading references the prin- 
cipal sources of more detailed and technical informa- 
tion on copper. 

In gathering the material for this book I have had 
the aid and encouragement of so many people that it 
would be difficult to thank them all. I am especially 
erateful to Dr. Edwin E. Slosson, director of Science 
Service, for his constant advice and criticism and the 
models of popular science writing that are furnished 
in his books. I want to acknowledge the cooperation 


that I have received from Mrs. Davis in the writing 
vii 


Vill FOREWORD 


of this book. Without her encouragement, without 
her collaboration on the portions of the volume that 
treat of chemistry and art, without her constant aid 
in checking the information and typing the manuscript, 
the completion of this book would have been im- 
possible. Among those to whom I am especially 
erateful for advice, information, and criticism are: 
Dr. Walter Hough of the Smithsonian Institution, 
Dr. T. T. Read of the United States Bureau of Mines, 
Dr. W. F. Meggers, Dr. G. K. Burgess and Dr. H. 8. 
Rawdon of the United States Bureau of Standards, 
and Captain H. A. C. Jenison of the United States 
Geological Survey. 
Watson Davis. 


INTRODUCTION 


One who is writing the history of copper does not 
have to arouse an interest in the subject. He has 
only to maintain and extend it. 

For every one knows copper, however little he may 
know about it. The first object to attract the infant 
eye was very likely the brass knob of a bed or door. 
He early learned the monetary value of the metal by 
finding that it was legal tender for saccharine delights 
at the candy-shop or slot-machine. 

So also in the childhood of the race was copper the 
first known of the useful metals. Some savage scien- 
tist, unknown to fame, picked up a piece of jagged red 
rock that seemed more serviceable as a knife than the 
familiar flake of flint. But when he tried to sharpen 
the edge with a stone hammer he found that instead of 
_ chipping off in little shell-shaped scales, the strange 
material gave way beneath the hammer-blows with- 
out breaking and so could be beaten into any desired 
form. 

We may imagine the pride with which the prehistoric 
inventor exhibited his new-fangled knife or spear-head 
to his tribesmen, but we may also surmise that they 
laughed at him for carrying around such a queer con- 
traption, and that when he demonstrated its superior- 
ity over flint he was robbed of his invention by some 
less original but stronger warrior. For we cannot 


suppose that troglodyte society was so superior to 
ix 


a INTRODUCTION 


ours that an inventor would then meet any better fate 
than he does nowadays. 

Comparatively few people know how beautiful cop- 
per is because comparatively few people have ever 
really seen it. What most have seen is but the painted 
face of copper, the mask it puts on when exposed to 
the world. To see the metal as it really is one must 
strip it of its concealing coat by heating it to red- 
ness in a glass tube through which hot hydrogen gas 
is streaming. Then the copper is revealed as a shin- 
ing silvery metal, delicately tinted with pink, like the 
inner petals of a rose, less gaudy than gold, less steely 
than platinum. 

But draw the copper from the closed tube and let 
a breath of air strike it and instantly a red blush 
spreads over its face, deepening to a red flush as a 
baby’s skin burns in a seaside sun. This soon dark- 
ens to a dull bronze, and further action of the air 
and moisture gives it a greenish or bluish tint. This 
fine patina is highly esteemed by artists and anti- 
quarians on roofs and statues, but our municipal au- 
thorities call it ‘‘verdigris’’ and scratch it off occa- 
sionally with a sand-blast. They had better leave it 
on for both esthetic and economic reasons, for the 
bare metal cannot stand exposure, and no paint is 
more protective than this that is made by the atmos- 
pheric agencies against which protection is sought. 
Coins and castings, coated with the patina, are pre- 
served intact for thousands of years though buried 
in the damp soil where iron implements would soon 
vanish in a heap of rust. : 

The readiness with which copper forms affinities 
with various elements gave it the name of ‘‘the mere- 


INTRODUCTION x1 


tricious metal,’’ as the alchemists called it. But this 
very versatility has its value for human needs, since 
copper in combination assumes many beautiful and 
useful forms. The greens and blues of malachite and 
azurite are gorgeous as any gems, yet they may be 
had in masses large enough to make table-tops and 
mantelpieces. Glass and pottery get various hues 
from traces of copper, and ‘‘blue vitriol’’ is equally 
familiar to the electrician and to the horticulturist. 

Copper is a good mixer. It enlarges its field of use- 
fulness by alliances with other metals. Tin gives it 
the hardness of bronze. Zine gives it the golden 
glitter of brass. With nickel and zinc it makes a pass- 
able silver. With aluminum, which man has lately 
learned to extract from common clay, it forms new and 
useful alloys. The noble metals, gold and silver, in 
their proudest capacity as coins and jewelry gain 
strength by combination with the more plebeian 
copper. 

Copper got its fame from the fairest of the god- 
desses, who chose it as the metal for her mirror. This 
was, it must be confessed, ‘‘Hobson’s choice,’’ for 
Venus is older than she looks, and when she rose 
from the sea, somewhere off the island of Cyprus, her 
first request was for a looking-glass that she might see 
for herself the reason for the admiration she per- 
ceived in all men’s eyes. She was not content like 
Narcissus with the pallid reflection of a pool, which 
besides could not be carried around with her, and so 
she sought for a suitable metal. There were only two 
known at the time, gold and copper. Gold she re- 
jected; not, we must assume, on the ground of ex- 
pense, for Venus has never lacked admirers eager to 


xi INTRODUCTION 


pay for her luxuries, but probably because gold cast a 
sallow tinge on her countenance, while copper bright- 
ened the tint of her auburn locks and endowed her 
cheeks with a blush like that of modest maidens. 

Anyhow the looking-glass of the Cyprian Aphrodite 
became the symbol of her sex and is still to be found 
as such ? in our modern manuals of botany and 
zoology. 

The cyprium from the Cyprian isle became the cu- 
prum of the Romans and the copper of the English, 
and the metal from which was fashioned the jewelry of 
goddesses and queens was made into pots and pans 
and cheapest of coins. A copper button that was 
proudly worn by a Pharaoh of 4400 3.c, has been 
found in an Egyptian tomb, but it is not nearly so 
elegant as the buttons that the elevator-boy laa 
displays on his uniform. 

‘“Not worth a copper,’’ is the nadir of value, yet 
copper is worth much to the world and never more 
than now in this Age of Electricity. Light and power 
are conveyed to our cities and homes by conduits of 
metallic wires through which flow streams of minute 
electrons as water flows through pipes. But it makes 
a great difference in the freedom of the flow what 
metal is used for the wire. Here copper comes into 
play, for its conductivity is almost as good as that 
of silver and much better than iron. A pure copper 
wire will convey five and three quarters times as much 
current as an iron wire of the same diameter. 

But the copper must be pure. Even the minutest 
admixture of some other element will impede the 
electrical current just as a little dirt in a water-pipe 


INTRODUCTION X1il 


will keep us standing in the cold waiting for the bath- 
tub to fill up. Copper is almost human in its sen- 
sitiveness to poisons, Arsenic to the amount of 0.0013 
per cent will lower the electrical conductivity of a 
copper wire by 1 per cent. This infinitesimal amount 
of arsenic, little more than one part in a hundred thou- 
sand, would therefore reduce the range of the tele- 
phone wire from a hundred miles to ninety-nine and 
add correspondingly to the cost of service. So the 
electricians have demanded of the refiners delivery in 
thousand-ton lots of copper more free from foreign ele- 
ments than that which used to pass in the laboratory 
as ‘‘chemically pure.’’ 

If the cloud of smoke is to be lifted from our cities, 
if our factories are to be made clean and our homes 
convenient, by the substitution of electric power for 
coal burning, it will be by aid of this humble element. 
Copper is not so conspicuous as steel yet it is almost 
as indispensable to the maintenance of modern civ- 
ilization. Itis to increase the popular appreciation of 
the importance of copper that this book has been writ- 
ten. Here my colleague in Science Service, Mr. Wat- 
son Davis, has told ‘‘The Story of Copper’’ in a way 
to interest those who have no special knowledge of 
chemistry or concern with metallurgy. Yet I think 
even those who consider themselves well informed on 
the subject will find some things new to them as they 
turn over the pages. 

Epwin EK. Stosson 
Director of Science Service, Washington. 


AS) 


CHAPTER 


CONTENTS 


Man’s Bronze Key to CIvmnizaATION . 
THE GENESIS OF COPPER 

THe EartH’s HERITAGE OF COPPER 
WINNING METAL FROM THE HartTH 
From Eartu to Inegors 

CopPER’sS INSIDE STORY . 

CopPER’sS CHEMISTRY 

CopPER’S JUNIOR PARTNERS 

Putting CoprpeR AND Brass TO WoRK 


Tue Merauutic SERVANT OF ELECTRICITY . 


Burtt oF COPPER 

CopPER IN THE HomE 

DoInG THE WORK OF THE WORLD . 
CopPER’S COMPOUNDS 

THE BRASS AND BRONZE OF War . 
Bronze BEAUTY . 

CopPER’s FuTURE 

READING REFERENCES ON COPPER 


INDEX . 


xV 


2 


* 


LIST OF ILLUSTRATIONS 


Symbols of American Freedom . 


Frontispiece 


First Americans mining copper . 


A reconstruction of a primitive furnace at the Royal 
School of Mines ae 


Location of the tin and copper mines that are known to 
have been worked by early man 


Egyptian figure of the sixth century, B.c. 


The four bronze horses at the main entrance of St. 
Mark’s Cathedral, Venice . eetlel, 


Brass sanctuary knocker, now adorning the door of Adel 
Chureh, Yorkshire a oat ees MPT ato Oe Soi: 


The famous Snake Column of Constantinople . 


American Indian implements and ornaments of pre- 


Columbian days . 
The cartouche, or name plate, of Tut-Ankh-Amen . 


Two slightly different forms in which the ancient al- 
chemists employed the ‘‘Ankh,’’ the SyroboF of 
enduring life, to designate copper : 


Some of the principal ores of copper . 
Chaleopyrite ore 


Diagram showing how native copper occurs in conglom- 
erate lodes in Michigan deposits . Bae A 


Diagram showing how nature hides a wealth of concen- 
trated copper ores under a lean capping of worthless 


iron ore 
xvii 


PAGE 


13 


16 
16 


16 


16 
16 


LT 


24 


24 
32 
33 


48 


49 


XV11 LIST OF ILLUSTRATIONS 


PAGH 
World production of copper . . . oe 
World’s copper production by decades 1810-1920 . . 58 
Copper producing areas of the United States. . . 65 


Chart showing rank of States producing copper 1845-1921 66 
A mountain of copper (9.00.0. 
The great copper ‘‘camp’’ of Butte, Montana . . . 81 
An electric ‘‘mule’’ .) . . °...., 4) 
Looking down the shaft of one of the Butte mines . . 96 


¢ 


The immense converters at the Anaconda reduction works 
at Anaconda, Montana... .. ) see 


Sixteenth-century methods of descending into a mine. 99 


How the copper-bearing material flows from ore-cars to 
ears that carry blister copper to the refinery. . . 102 


Roasting copper matte .  . 6). ies een 
Smelting copper ore . . |. 5 See 


Chart showing the principal features of the copper in- 
dustry 1913-21... 20 0) Se 


Photomicrographs of copper’s different appearances. . 152 


Atom planes of copper sulphate . . «7 es 
Map of brass... 006 6) = a) 
Structure of various brasses seen through microscope, 

magnified 100 times...) . 3 ee 
Spectral proof that brass contains copper and zinc. . 193 
Cheese-like structure of leaded brass .) 92) 3) ve 
How prolonged heating will change the inside appearance 

of an alloy =. 0. 005. 0 
Map of copper-aluminum alloys . . . . . =. . 196 


Map of copper-nickel alloys*. . . 2) 3 0 sleene 


LIST OF ILLUSTRATIONS x1X 


PAGE 
Map of bronze. ... Ny Yay ay eA Uy ree mea ened bb 
Pit furnaces in a modern brass casting shop. . . . 240 
Pouring brass from electric furnace into molds. . . 240 
Meee esheets OL copper. . . . . . « wi. « 241 
The machine that extrudes plastic brass like so much 
eS ip ce eg ec ee ge ee we OAL 
PERCU UCS eh ke ee we ew, 208 
Ta WITOg ig Gk ee te OT 
Overhead copper wires ... . Me mere (. 


A bronze buddha aeaDes any, the Tapaness for 
centuries . . . 296 


Trinity Church, one of the oldest of New York’s land- 


marks, roofed with coppercci fs. . 296 
Weights dating back to the time of Washington. . . 297 
etiesstuatwnave been history. . . . ... + . 297 


Sketch showing the way in which copper and brass are 
used in a 75 mm. shell, high explosive nose, fuse type 324 


Hvolution of a rile cartridge . =. ... . . . . 828 
ee. (O 8. ss we es we we OLD 
Distinguished Service Cross. ... + . + « « « d29 
(Bee es gcc eS a sans Se 3) 


eT Gg eh aw oe ee OD 


AN 


THE STORY OF COPPER 


THE STORY OF COPPER 


I 
MAN’S BRONZE KEY TO CIVILIZATION 


About ten thousand years ago, not so long in the life 
of humanity, some Neolithic man selected a chunk of 
reddish ‘‘rock’’ from a crevice in the earth and found 
that this strange material made a battle mallet that 
was superior to the stones of his adversaries. He 
sang the praises of the new ‘‘rock’’ to his tribesmen, 
and in the secrecy of night, perhaps, his group 
of stone age warriors quarried and armed themselves 
with better weapons of a new era. 

What ameba could predict man? And what first | 
copper-using tribesman could see, three hundred gen- 
erations in the future, a modern copper-capped city, 
sending light, heat, and power through copper, talk- 
ing and singing over copper, drawing on copper pic- 
tures that multiply themselves a thousand times, and 
using copper coins by the millions? 

Probably the news of the new red ‘‘stone’’ and the 
place that it would be found leaked out in time, 
through a new age warrior who was careless enough 
to get captured by the old age enemy. Then the 
metallic age began in earnest. The Neolithic man be- 
came eometallic man, or, to translate the anthropol- 

3 


A THE STORY OF COPPER 


ogist’s and my improvised Greek, the man of the late 
stone age transformed himself into the first man of a 
new and wonderful age of metals. 

How long he continued to call this reddish native 
metal by the same Neolithic word or grunt that he ap- 
plied to all the other rocks, no one knows. In fact, 
we must set our imaginations at work to reconstruct, 
as we have done, the discovery of copper; six to eight 
thousand years before the birth of Christ is far too 
early for any sort of man-written, time-binding record 
to come down to us. 

We can further imagine, synthetically, that there 
came a time when some early human being, putting a 
smoother curve on his copper mallet, found that with 
a hard piece of rock he could laboriously hammer and 
beat one side of it into an edge that was sharper and 
deadlier. It became a better weapon. There was a 
distinct difference between it and the stones of the 
era past. As the inventor searched his mind for a 
prehistoric word meaning ‘‘malleable stone,’’ he took 
a step forward. 

The place where copper rock was found undoubtedly 
became a center of commerce, for the new kind of ax 
was desirable for the ways of peace as well as those of 
war. Unlike conditions to-day, through the use of 
the same tool the man of those early times was able to 
provide his family with meat and other necessities and 
to protect them as well. 

At the first COr PS a fires were kindled to keep 
the copper man’s family warm, scare away the beasts, 
and cook the animals that fell under blows from his 
improved ax. 


KEY TO CIVILIZATION 5) 


Perhaps this went on for years; perhaps the red- 
dish rock that could be hammered: into axes grew 
scarce. It was no longer easy to find the hunks of it 
of the proper size in the rock cracks. Fathers talked 
of the good old times when copper axes were easy to 
win from the ground; sons treasured the worn weap- 
ons of their great-great-grandfathers. But they 
still worked in the pits or open mines made by the 
copper hunting of the past generations, and were 
rewarded by infrequent finds of the malleable rock. 
Scarcity of copper rock may have been a subject of 
grave debate in tribal councils. It probably was a 
cause of battle when the strong wrested from the 
weak, but luckier, the better mines that they were 
working. , 

We may imagine an economic and martial council 
around the fire. Inadequate copper is being discussed. 
One sub-chieftain after another waxes eloquent in 
urging his particular scheme for relieving the situa- 
tion. ‘‘There are rumors of better, richer mines to 
the west,’’ says one favoring battle with the happy © 
possessors. ‘‘Stone axes were good enough for the 
fathers of my father,’’ declares a prehistoric, gray- 
bearded reactionary; but such a suggestion for a re- 
turn to the old order is laughed down by the progres- 
sive younger element that now has to fight the battles. 
Talk goes on until the dying embers of the pit fire 
tell them it is late and that it is time to feast on the 
little dog roasted for the occasion deep beneath the 
hot bed of embers. The most utilitarian and least 
favored wife of the entertaining chieftain digs into 
the pit, which had ,been constructed from débris of 


6 THE STORY OF COPPER 


the copper rock quarry, and begins to remove the glow- 
ing coals confined in the hollow. 

‘*Hot!’? murmurs a thoughtful chief. ‘‘Hotter than 
the fire that sweeps the forest or opens the moun- 
tain!’’ 

‘“You should have a stick of copper,’’ says another, 
as the flattened stick-shovel of green wood bursts into 
flame in the intense heat. 

When she has nearly reached the thoroughly baked 
thick clay case of the deliciously cooked puppy, Mrs. 
Chieftain can hardly believe her eyes. 

‘‘The rocks have turned to fiery water!’’ she ex- 
claims as she sees a pool of glowing liquid. But as 
she watches and the others crowd round, the redness 
fades out. 

‘‘We only thought we saw,’’ says one. 

‘An omen,’’ declares another. 

‘‘Perhaps,’’ says the thoughtful one, ‘‘we shall see 
when morning comes.’’ 

‘‘Let us feast,’’ invites the host. And what group 
of weary men, tired of talk, would not? 

That night the thoughtful chief dreamed rivers of 
reddish, fiery liquid sweeping over and annihilating 
his enemies. Before the sun rose he was raking over 
the ashes of the festal fire of the night before. No 
liquid was there. But he found a strange stone, black- 
ened, and shaped like a frozen puddle. He wondered 
at it, and tried to crack it with a stone quarry sledge. 
It did not split asunder, but the blow left a dent, a 
mark that was like that left on the valuable reddish 
rock of the quarry that was so much desired. Cop- 
per? A scratch penetrates the black coating of the 


KEY TO CIVILIZATION ff 


new fire-stone and shows a reddish metallic gleam. 

‘*Yes,’’? sneers old gray-beard, when the find was 
shown to a hastily called council of half-awake chiefs, 
‘‘I remember, when the malleable stone was not so 
scarce, we sometimes found ax-size hunks in the ashes 
of the fire pit into which they had dropped. They were 
carelessly overlooked in quarrying. With all the care 
of quarrying to-day, that could happen even now.”’ 

Hiven in twentieth century metallurgy a new method 
is not achieved in a day. Years may have passed be- 
fore concentrating ‘‘worthless’’ discards into usable 
chunks of copper was reliably used by prehistoric man. 
The dreaming chief and his devotees may have spent 
their lives proving and improving the first application 
of fire to the extraction of metals. 

It was probably in this manner, complex to them al- 
though simple to us, that our ancestors launched the 
metallurgical age, during which man won hidden metals 
from unpromising earth and used them as he wished. 

After the discovery that metal will melt, it must have 
been but a short step to casting it. The observant 
barbarian must have noted that the rough mass of cop- 
per took the shape of the hollow in which it solidified ; 
then, perhaps, one day after he had become tired of 
hammering axes into shape he pondered over this. 
He may have thought the matter out and completed 
his brain-work by pressing his favorite ax into the 
earth and forming a mold into which a new ax could be 
formed. Or this advance in copper metallurgy may 
have come about by accident as so many things do; 
into an accidental ax slash in the ground some molten 
copper may have been spilled, forming an ax blade 


8 THE STORY OF COPPER 


that suggested to the improving mind of man a better 
way to manufacture his tools. 

Our story of how the use of metals began is merely 
a good guess. The human race struggling upward 
through the stone age and the early part of the age 
of metals left few traces of their troubles before 
1000 8.c. We have only scant Egyptian records, the 
evidence that is contained in the Scriptures, and in- 
cidental references in that source of oldest pre-Con- 
fucian history of China, the Shu-King, sometimes de- 
scribed as the ‘‘Canon of History.’’ By the time that 
the fifth to the third centuries, B. c. have been reached, 
there is a more extensive Greek literature that gives an 
insight into the metallurgy of that time. During the 
four to five thousand years from the time when man 
began to use metal until we have reliable written 
records,—a space of time about twice as great as the 
extent of the Christian era,—there is little recorded 
evidence. We must rely on our deductions from the 
objects that appear in the remains left by these early 
peoples. 

So vague and mysterious are the beginnings of 
metallurgy that many of us may be tempted to shirk 
the task and adopt the explanation of William Pryce, 
who wrote 150 years ago: 


It is very probable that the nature and use of metals were 
not revealed to Adam in his state of innocence: the toil and 
labor necessary to procure and use those implements of the 
iron age could not be known, till they made part of the curse 
incurred by his fall; ‘‘in the sweat of thy face shalt thou eat 
bread, till thou return unto the ground; in sorrow shalt thou 
eat of it all the days of thy life’’ (Genesis). That they were 


KEY TO CIVILIZATION * 


very early discovered ; however, is manifest from the Mosaick 
account of Tubal Cain, who was the first instructor of every 
artificer in Brass and Iron. [‘‘Brass’’ of the Bible is not 
the alloy of copper and zinc, but copper alone. The mistake 
arose in translation. ] 


But I think that it will be more accurate and even 
more interesting to learn what the archeologists and 
anthropologists have found out about early man’s 
metallic entrance into civilization, even though we have 
to do a little guessing or accept theirs. It will whet 
our imaginations, which is not an unpleasant experi- 
ence. 

Perhaps copper was not the first metal to which 
man introduced himself. In the sands ofa river-bed 
a nugget of yellow may have attracted a man’s eye and 
he may have taken it home and given it to a woman. 
Gold is a useless metal despite the present-day rever- 
ence for-it. Even now the gold of our double eagles 
has to have copper, one part in ten, to reinforce it and 
prevent it from wearing away. Our first gold was a 
woman’s pretty bauble, probably nothing more. 

In the same way, red metal nuggets, worn by water 
and blackened by air, may have been found by man be- 
fore the source of the native copper higher up in the 
mountains was found and exploited for battle-axes. 
But finds of such alluvial metal were probably mere 
incidents in pre-metallic times, or they may have fur- 
nished occasional better stone-type tools that caused 
man quickly to recognize and appreciate copper when 
it was revealed to him in the pit fire or native in the 
rocks. | 

When man used fire to loosen the hold of rocks and 


10 THE STORY OF COPPER 


elements upon copper, then metallurgy as a use- 
ful science came into being. 

Copper as a native, free metal, such as has been de- 
scribed in our hypothetical opening scenes of the metal 
age, did not long satisfy the needs of an improving 
world. In some manner, it was discovered that a 
pretty red earth, suggestive in color of copper, actu- 
ally was in part this metal and that the heat of blown 
fire would unlock copper from its oxide if this ore was 
underlaid with charcoal. When this was accomplished 
it must have been a transmutation far more wonderful 
in that day than if some miracle-worker of to-day 
suddenly turned lead into gold for us. Was the first 
smelting of copper ore consummated in a pit fire that 
was blown into high heat by the puffed cheeks of an 
inquisitive experimenter? Perhaps. We know that 
in some such way the method of building a primitive 
furnace was puzzled out, and the reward was copper. 
Once the secret was discovered, crude methods gave 
way to better ones. Human bellows were supplanted 
by some mechanical arrangement, such as the fan- 
like hand blower that is used with the braziers and 
small cooking fires in many parts of the world, and 
this in turn gave way to better draft-producing de- 
vices. | | 

After this metallurgical method had been tried for 
a few centuries men probably discovered that all red 
earth for copper-making was not the same. An ax 
made from the ore of one mine seemed to be strangely 
harder than one made either from different red earth 
or from the native metal. The owner of the harder 
ax probably rejoiced and remained content in the 


KEY TO CIVILIZATION a 


possession of a superior weapon. Bearers of inferior 
axes scratched their heads and looked around for a 
reason. Eventually a difference in the look of the 
better ore and ax led man to the realization that he 
had something new in metals—bronze. 

Archeologists differ among themselves, and arche- 
ologists and metallurgists disagree widely in their be- 
liefs as to how the first alloy, a combination of copper 
and tin, was first made. Some believe that it oc- 
curred in the way that has been described, by the smelt- 
ing of a combination of copper and tin oxides mixed 
together in nature’s veins in approximately the right 
proportions for man’s use. Others reconstruct for 
themselves the picture of separate smeltings of the 
red earth that gives copper, and the metallic-looking 
alluvial cassiterite, oxide of tin, found in beds of 
streams. They see man with these two metals, one 
of which he does not know well; and they naturally 
suppose that he tried to mix them and that a service- 
able bronze was the eventual result. 

Again, we may imagine a primitive furnace turn- 
ing oxide ore into copper. Coming in from an ex- 
pedition, a tribesman, perhaps, showed the furnace- 
tender a handful of metal-like tin oxide nuggets that 
he had found among the stream-bed rocks that were 
used to make the stone implements which copper had 
not supplanted. They decided to add this material 
to the copper, and bronze resulted. 

All three of these methods of making bronze may 
have come first in different places, but that brings 
us to another disputed question, whether there was 
more than one beginning of the age of metals. We 


12 THE STORY OF COPPER 


are fairly sure that in Mexico, before the white men 
spoiled a growing culture, the Aztecs smelted a natural 
bronze from a mixture of copper and tin ores. But 
except for such isolated cases, evidence seems to favor 
a separate smelting of the ores and alloying the two 
metals as a third operation. 

For our reconstruction of the bronze age furnaces, we 
have more than our imaginations alone to draw upon. 
In parts of Europe, many ‘‘founder’s hoards’’ or 
‘‘smelter’s hoards’’ of the bronze age have been found. 
Their rude round copper cakes, eight to ten inches in 
diameter, have taken the shape of the bottom of the 
pits. In Egypt archeologists have found a few pic- 
tures of crude furnaces and bellows, which show that 
as early as 2300 B.c. there had been a considerable 
advance over the crude hearth. By analyses of early 
copper tools we learn that little sulphur is present, 
and we are thus able to say that it was oxide ores, not 
sulphides, that were first smelted. 

Archeologists and anthropologists also use a ‘‘ back 
to nature’’ method of determining the most probable 
methods of bronze ageman. They imagine themselves 
transported to ancient times; they use the tools of 
that age, and then, pitting their own skill against that 
of their ancestors, attempt to do what they must have 
done under the conditions of their times. This method 
has been used more than once to help settle contro- 
versies. It is still a question, as I have said, whether 
the copper and tin in old bronze occurred naturally 
in mixed ores, or whether the two metals were smelted 
separately and then alloyed. Professor William Gow- 
land was a strong believer in the mixed ore theory, but 


KEY TO CIVILIZATION 13 


BG $7" 


Pike te 
A RECONSTRUCTION OF A PRIMITIVE FURNACE AT THE ROYAL 
SCHOOL OF MINES — 


In such a hole in the ground Bronze Age man is supposed to have smelted 
malachite to obtain copper or malachite and tin-stone to obtain bronze 


14 THE STORY OF COPPER 


there were others who said that bronze could not be 
produced in that way, as the tin would go off in the 
slag. In the floor of the Royal School of Mines, Pro- 
fessor Gowland reconstructed a primitive furnace, such 
as must have been first made four or five thousand 
or more years ago, and became a strong-lunged metal- 
lurgist in the making. From a mixture of green car- 
bonate and tin-stone, in such a furnace, with charcoal 
for fuel, he smelted bronze containing twenty-two per 
cent. of tin that would have pleased the most advanced 
inhabitant of the bronze age. Many of the American 
Indian ornaments that date before Columbus’s voyage 
across the Atlantic are such wonderful examples of the 
coppersmith’s and jeweler’s arts that some have 
doubted their early origin. Several archeologists 
have equipped themselves with wood, stone, and cop- 
per Indian tools, foresworn steel and iron, and proved 
by action that such primitive tools in the hands of a 
man could have produced designs in copper that are 
valued to-day as much for their workmanship as their 
antiquity. 

To-day we say ‘‘brass and bronze’’ in the same 
breath. The two words sound well side by side, and 
the two materials work and look well together. It is 
hard to realize that civilizations rose and died between 
the invention of bronze and the invention of brass. 
As has been described, bronze came into use at least 
earlier than 3500 B. c.; brass was not used until shortly 
before the Christian era. Brass is less than half as 
old as bronze; a stretch of time a thousand years or 
more longer than the Christian era separated the 
initial use of these two important alloys of copper. 


KEY TO CIVILIZATION — 15 


There is a reason for this. Brass is‘much more dif- 
ficult than bronze to make and cast, and zinc is a metal 
that likes oxygen much better than does tin, copper’s 
partner in making bronze. When zinc is heated, it 
burns and changes to a white vapor, zinc oxide, if it 
is given an opportunity to snatch the necessary oxygen 
out of the air. While the burning of zinc into oxide 
is a profitable present-day operation and results in 
white pigment for paint, it hampered ancient brass- 
making. However, zinc as a metal was not known to 
the brass-makers of the time shortly before the 
Christian era; in fact, it was not until the middle of 
the sixteenth century a.p. that zine in its free state 
was actually used and identified. An earthy sub- 
stance, the ore calamine, a hydrated zine silicate, was 
the material which the metallurgists mixed with cop- 
per to form brass that is called aurichalcum in early 
Roman writings. It was not until modern times that 
spelter, as the metallic zinc of commerce is called, came 
to be used. 

It was Dioscorides who gave in his writings the first 
description of the method of securing pompholyz, zine 
oxide, as follows: ‘‘The soot flies up when the copper 
refiners sprinkle powdered cadmia over the molten 
metal.’? He thus indirectly leaves the first definite 
indication of making brass. From him also we learn 
for the first time of copper made from sulphide ores, 
for though he was writing a medicinal treatise, he 
states that ‘‘pyrite is a stone from which copper is 
made.’’? How late it was that man became acquainted 
with the sulphide ores that to-day furnish two thirds 
of all the copper produced in the world! This same 


16 THE STORY OF COPPER 


LOCATION OF THE TIN AND COP- 
PER MINES THAT ARE KNOWN TO 
HAVE BEEN WORKED BY EARLY 
MAN 


Egyptian figure cf the sixth century B.c. The four bronze horses at the main 
typifying the flight of time. Made of entrance of St. Mark’s Cathedral, Venice. 
bronze. Originally erected in Rome, sent to Con- 

stantinople by Emperor Constantine, they 
were brought to Venice in 1204. 


Brass sanctuary knocker, now adorning The famous Snake Column of Con- 
the door of Adel Church, Yorkshire, which stantinople, exposed to the weather since 
has served in England since Cromwell’s 479 s.c.. It was originally a votive offer- 
time 


ing to the Temple of Apollo at Delphi. 


‘yIOX MON pue ‘eiuealAsuusg ‘AyonJUay ‘eIUISITA SAM ‘OIYQ Worf sued JUIOS jnq ‘UTSUODSITAA Ul poy}ivaun 
a1aM S}UsUIa{duII ay} JO YSOJL ‘zpe Ulopou e& ayI[T JeYMouTOS st Y YM ‘pnds e poaijeo juswajdm1 ue st ‘ajpuey e 1O0¥ uUOIsso1dap 
e YUM opelq 94 ‘“JUOUTeUIO Ivo UB sI yOaf[qO PajJUapUI pUNoI sY [Me Ue SI POL Japusls ay} aIyM ‘s}o0 pa[eo ‘s}yuswayduit 
Suryoey jo sepelq 94} 91e 91njzoId JY} FO YSII dy} 0} syoafqo aB1e_ ayy, ‘syurod ayoafoi1d jo jusuI}1OSse Ue SI Speaq 94} MOTAq }J2] 
24} OL ‘poo} Surredoid ut smenbs ueipuy 94} Aq pasn a19M saAluy podeys uoow-jey ey4y, ‘juIod Jassep eB pue S2ATUY INO} o1e 
a19y} speaq oy} JO 3YSII 9Y} OF, “YSvaIq OY} UO UIOM ST YOIYM JO Jasiel 9Y} “S}UDUIeUIO OM} JIB }J9IT Il9y} OF, ‘spveq jo sur1ys 
yews eB pue jyoysov1q Joddoo e& st avy} speaq taddoo jo aov[yoou |3Y} UIYUAA ‘s}uIOod MO11e pue ivads paqieq aie doy 94} 1V 


é 


SAVG NVIGWN'IOO- dad JO SLNANVNYO: GNV SLNAWAIGWI NVIGNI NVOTSANV 


wnasnw [euoneN “S ‘fQ 2y} Jo Asayanog 


KEY TO CIVILIZATION ay 


Greek writer also gives us our first description of 
blue vitriol, the common chemical, copper sulphate, 
and aptly describes the pieces as ‘‘shaped like dice 
which stick together in bunches like grapes.’’ 

That is the story of the discovery and early metal- 
lurgy of copper as well as we can tell it to-day. Who 
took these steps and when they were taken are ques- 
tions whose answers are quite as vague and quite as 
interesting. It may be that the use of metals began 
independently in different parts of the world, but it 
is equally probable that metallurgy, or the use of 
fire in working metals, originated from a single 
nucleus and spread gradually to other parts of the 
- world. 

The main part of Africa is the only great world area 
on which an age using copper or bronze is not recorded. 
In Asia, Europe, and the two Americas evidences of 
the use of copper metals are to be found abundantly. 
But the richest of archeological storehouses are to be 
found in the parts of eastern Asia Minor, western 
Europe, and northern Africa that border upon the 
Mediterranean. In this cradle of culture archzolo- 
gists have unearthed most of the relics and indica- 
tions that bring to us the history of prehistoric peo- 
ples. 

It was in Mesopotamia, perhaps, that man first found 
copper. His introduction to this first metal may pos- 
sibly have been through his discovery of native cop- 
per in the veins of rock, but more likely he either found 
usable chunks of it in stream beds or, by some happy 
chance, learned how to smelt the oxide ores. Again, 
it may be that Egypt was copper’s Garden of Eden 


18 THE STORY OF COPPER 


rather than the fertile, sunny country between the 
Tigris and Kuphrates rivers, in which, according to 
biblical lore, man’s origin took place. We do know 
that after an Egyptian stone age of great skill copper 
began to be used. In the early Egyptian graves, which 
serve as the record-books for us to read to-day, there 
came a time when the weapons and utensils left for the 
use of the dead were not of stone but of metal. Per- 
haps this was 5000 B. c. 

The stone age and the beginnings of the metal age 
in HKurope, in addition to being of very uncertain 
date, have only recently and incompletely revealed 
themselves to archeologists. It is not certain whether 
the Neolithic pastoral people who left those early re- 
mains were the direct ancestors of the later copper- 
using Egyptians. In many respects the later and more 
advanced people differed entirely from their pred- 
ecessors. For three dynasties copper is the only 
metal that is found in the prehistoric Egyptian re- 
mains, but as early as the fourth dynasty bronze arti- 
cles have been found. This dynasty marked the cul- 
mination of the Old Kingdom, and it was a period 
of wealth and splendor. A passion possessed its 
monarchs for making monuments to glorify themselves, 
and it was then that the vast stone piles of the Great 
and the second and the third pyramids were erected. 
Depending upon the authorities that are accepted, it 
was from 3800 to 4700 years before Christ that the 
kings of this dynasty raised their sepulchral piles. 
Vain, unmeaning, and wasteful as these pyramids may 
seem, they are interesting to us because in one of 
them, that of Medum, has been preserved a rod which 


KEY TO CIVILIZATION 19 


is the oldest piece of bronze that man now knows. 

Where the early bronze of Egypt came from is a 
mystery. We can account for its copper content, be- 
cause ancient copper-mines, while not found in Egypt, 
are scattered over those parts of Asia Minor with 
which the Egyptians had trade relations. Most of 
the Sinai peninsula, which juts out of Arabia into the 
north end of the Red Sea, was probably the first source 
of KEgyptian copper. There archeologists have 
found reliefs dating as early as the reign of the 
Egyptian king Seneferu, about 3700 B.c., indicating 
that he worked the copper-mines. The emblem of 
copper in the hieroglyphics is the crucible, and the 
finding of crucibles at Sinai indicates that the 
Egyptians even went so far as to carry on some form 
of refining. 

But assigning an origin to the tin is a different 
matter. The nearest cassiterite-mines known to the 
ancient world are either beyond the far end of the 
Mediterranean in Spain, France, and Britain or clear 
across the Asiatic continent in China. Within easy 
reach of Egypt we can find no traces of where the 
tin could have originated. Archeologists find it hard 
to believe that as early as 4000 B.c. the Egyptians 
traded with either western Europe or China, as they 
must have-done if they obtained their supplies of tin 
from either of these sources. It is true, of course, 
that the Phenicians, two and a half to three millen- 
niums later, distributed to the ancient world a supply 
of tin from Spain and Britain; but coupling up this 
trade activity with the beginnings of the bronze age 
is like speaking of the recent World War and the fall 


20 THE STORY OF COPPER 


of Troy in the same breath. Slender threads point 
to the yellow Hast as the source of tin and perhaps the 
knowledge of metallurgy. A mining engineer’s opin- 
ion on the origin of Kgypt’s tin is that it was a home 
product. Herbert Hoover, who, with Mrs. Hoover, 
translated Agricola’s ‘‘De Re Metallica,’’ suggests 
that alluvial tin may have existed within easy reach 
and may have become exhausted long before modern 
man had a chance to see it. How quickly such a source 
of metal supply can be forgotten, with no evidence 
remaining, is indicated by the seldom-remembered al- 
luvial gold supply from Ireland. Large tin fields of 
central Africa were discovered in relatively modern 
times, and native-made tin ornaments were found in 
circulation among the negroes there. These facts 
present the possibility of another tin source near 
ligypt, and the trade routes into Africa may have been 
the paths of entrance of the metal into Egypt. 

If we knew more of what was happening in China 
at that time, some of these metallurgical mysteries 
might be solved. The Chinese worships his ancestors 
so reverently that archeologists even to-day have 
great difficulty in searching the burial-places of that 
great country. Lacking the information that this 
would give them, they can only surmise what was the 
state of Eastern progress before about 2500 B. c., when 
the great pre-Confucian epics of the Shu-King men- 
tion the use of copper. Shortly afterward we know 
that bronze and copper were extensively used. Un- 
like Egypt, China has her mines of copper and tin 
side by side, and we do not wonder about the source 
of these metals for bronze. Bronze vessels of earlier 


KEY TO CIVILIZATION 21 


Chinese times, particularly those of the Shang dynasty 
from 1766 to 1122 B.c. and the Chow dynasty from 
1122 to 255 B.c. are beautiful; often they are inlaid 
with gold and silver. They are distinctive and have a 
style of their own, and we may better appreciate these 
products of the early Chinese culture by reading the 
poetical prose description of a relatively modern 
Chinese archeologist writing in 1767: 


Bronze vessels buried in the earth for a thousand years be- 
come pure blue, like that of the kingfisher. The color before 
noon is pale, but after noon takes on the appearance of clouds, 
and the kingfisher blue seems as if it would liquefy into 
drops. Bronze vessels subject to the influences of water for 
a thousand years become pure green, as the rind of a melon, 
and glossy like jade. If subjected to such influences for a 
shorter time, although they may be bluish green, yet they are 
not bright. 


In the kingfisher-blue and the melon-rind-green coats 
of these artifacts we to-day can identify the azurite 
and the malachite minerals to which a thin film of the 
copper during a millennium had reverted. 

Before the iron-armed Aryans conquered the orig- 
inal inhabitants of India, the northern part of that 
land had learned to use copper. As early as the late 
Vedic age, dating from 2000 to 1000 z.c., there are 
records indicating its extensive use, and from pre- 
historic times down to the seventeenth century there 
was a continuous existence of the copper industry. 
But unlike Europe and the rest of Asia, there was no 
Indian bronze age; the northern part passed directly | 
from copper to iron. Southern India did not even 


22 THE STORY OF COPPER 


have an era when copper was employed, but was still 
in the stone age when iron-using foreigners came into 
that country. 

From the focus of early origins in Egypt and an- 
cient Asia Minor, Hurope probably derived her knowl- 
edge of copper and bronze. As early as 3000 B.c., 
perhaps, metallurgical knowledge had been brought to 
Crete, and as centuries passed the bronze age crept 
over the rest of Europe, to Sicily in 2500, to France 
in 2000, and finally to Britain and Scandinavia in 
about 1800 s.c. This spread of the use of a metal 
may not have been a product of the peaceful advance 
of civilization, but more likely it was carried along 
with the irruption of an Aryan race into the west 
and north of Europe. It is entirely possible that in 
the thousands of years between the time when Medi- 
terranean man discovered copper and when the news 
and details of his accomplishment found its way north- 
ward, some of the north EKuropean races had made a 
few slow, independent starts toward using copper as 
a metal. About this we can only speculate, but after 
Egyptian culture had been distributed we know much 
about how copper and bronze were obtained and used 
by European peoples. 

In the word ‘‘copper’’ we have a living record of 
the mine that gave the early world a large part of its 
copper supply. Rome obtained most of its supply of 
this metal from the island of Cyprus, and for this rea- 
son called the metal @s cyprium, which was gradually 
shortened into cyprium and corrupted into cuprum, 
from which comes our word ‘‘copper,’’ the French 
cuiwre, and the German Kupfer. As early as 3000 B. c. 


KEY TO CIVILIZATION 23 


this island produced copper according to archeological 
research, and because of its mineral riches it passed 
successively under the domination of the Egyptians, 
Assyrians, Phenicians, Greeks, Persians, and Romans. 

The chemical symbol for copper that we use to-day, 
Cu, is of course the first two letters of the corrupted 
Latin word. But the graphic symbol for copper that 
was employed in alchemy can also be traced back to 
that famous island that furnished an early supply of 
the metal. Many hundreds of years before Christ 
there lived at the head of the Persian Gulf a people 
famed for their wisdom. These Chaldeans, aided by 
the clearness of their atmosphere, watched the planets 
and the stars from high places, seeking the relations 
between the heavens and affairs on earth. The skies 
played an important part in their lives (they believed 
so, which amounts to the same thing), and those peo- 
ples also linked the heavenly bodies with the gods and 
goddesses of their mythology. Wecan hardly realize it 
now, but in the early mythology, astrology, and al- 
chemy of those days were the beginnings of present- 
day religion, astronomy, and chemistry. Copper, the 
useful metal of the ancient world, was important in the 
three-fold association of metals, planets, and divinities. 
Venus, the planet, and Venus, the goddess, were sym- 
bolized on earth by red metal. Legend has it that 
Aphrodite, to use the earlier Greek name for the god- 
dess called Venus by the Romans, rose, full-formed, 
in all her beauty from the ocean’s foam on the shore 
of the island of Cyprus, which christened copper. 
Thus so firmly associated were copper and Venus, god- 
dess, and Venus, planet, that the alchemists of the 


po - 


-_——— 


24 THE STORY OF COPPER 


middle ages always represented copper by the astro- 
logical sign for Venus. ‘This circle with cross attached 


ia 


tA 


THE CARTOUCHE, OR 
NAME PLATE, OF TUT: 
ANKH-AMEN, CONTAINS 
THE SYMBOL LATER 
USED TO DESIGNATE 
COPPER 


: 


TWO SLIGHTLY DIF- 
FERENT FORMS IN 
WHICH THE ANCIENT 
ALCHEMISTS EMPLOYED 
THE “ANKH,” THE SYM- 
BOL OF ENDURING LIFE, 
TO DESIGNATE COPPER 


below was the Egyptian symbol 
for enduring life. It was called 
the ankh, which will be readily rec- 
ognized by the newspaper reader 
of to-day as the middle name of 
Tut-ankh-Amen, made famous 
overnight after an oblivion of 
thirty-five hundred years. The 
ankh may be seen in virtually any 
collection of Egyptian inscriptions, 
and among the relics in museums 
are specimens of the ankh in 
bronze. Since copper is supreme 
among the common metals in its 
everlasting qualities, the ankh in — 
our thoughts to-day may retain its 
early Egyptian meaning as well as — 
its later alchemistic symbolism for 
the metal itself. Those who have 
seen or studied the charts that the 
geneticist uses in making the fam- 
ily trees of plants and animals will 
recognize that the ankh, symbol of 
Venus, goddess of love and endur- 
ing life, is used to represent the fe- 
male while a circle with attached 
arrow pointing diagonally upward 
and to the right, the astrological 


and mythological symbol for Mars and the alchemistic 
sign for iron, is used to designate the male. What a 


KEY TO CIVILIZATION Ls) 


train of symbolism and ideas has run through the cen- 
turies connecting the material and spiritual portions of 
early days and the present time! 

Throughout France, Spain, and the rest of the Con- 
tinental area, as well as Britain and Scandinavia, the 
bronze-using people have left non-corroding traces of 
their daily life. Founder’s hoards, which seem to 
have been the stock in trade of itinerant founders, 
have been‘unearthed in many parts of Europe, and 
from the worn-out or broken implements, waste cast- 
ings, and rough lumps of copper and tin that they 
contain much has been learned. In early centuries the 
principal bronze products were flat axes, small knives 
and daggers, and small tools or ornaments, while 
swords, spears, and shields were unknown. The first 
metal objects that man produced had the same general 
shape and use as the stone tools with which he was 
familiar. After he had used copper and bronze for 
a time he shaped his weapons and tools so that the 
superior qualities of metal had a chance to show them- 
selves. When iron came into use the forms of imple- 
ments made of it were at first copied exactly after 
those of bronze. 

There are some archeologically inclined metallur- 
gists who dispute copper’s commonly accepted priority 
of discovery and believe that iron was isolated equally 
early and used coincidently. Their arguments do not 
rest alone on pieces of iron found in Egyptian remains, 
dating as early as 3700 and 3200 z.c., but they also 
_ point out the relative ease with which iron can be won 
from its ores. Iron is so plentifully scattered over the 
face of the earth that it seems logical to them that 


26 THE STORY OF COPPER 


early man should have first found out how to smelt 
hematite instead of copper ore. ‘The simplicity of this 
operation is well exemplified by the present inhabitants 
of a continent that never had a copper or bronze age, 
the hill tribes of northern Nigeria, where in native 
forges the negroes reduce iron sufficient for their 
needs. Bronze making, except in the few places where 
mixed ores are available, requires three operations, the 
smelting of copper and of tin and the mixing of these 
two metals, while the making of iron can be done in one 
step. Interesting as this reasoning is, it is true that 
for a long period during early history only copper and 
bronze implements seem to have been used. When 
iron appeared it was received as a substitute, and even 
for centuries afterward, when iron was the common 
thing, the veneration of custom and appreciation of — 
copper’s qualities caused the plentiful employment of 
copper and bronze. There is a bare possibility that 
iron was used coincidently with copper and its alloys 
and that, because of iron’s affection for the oxygen of 
air and water, iron objects have rusted away in the 
years that have passed. But despite this doubt, which 
iron’s instability has caused, we can safely set down 
bronze and copper as the key metals to civilization 
and culture. 

Old World archeology tells the story of early metal- 
lurgy as it affects our modern life to the greatest de- 
gree, but here on our own home continent, at a date 
close enough so that we can still have some living con- 
tact with it, there arose an independent copper age 
more interesting and vivid to Americans than similar 
and earlier progress across the water. 


KEY TO CIVILIZATION 27 


About the time when Mediterranean man was per- 
fecting his Neolithic implements preliminary to a 
transition into the metallic age, a few human beings in 
some way wandered across what is now Bering Strait 
into a new continent that man had not yet trod. It was 
in this way, so some anthropologists believe, that the 
beginnings of human life reached America. Thou- 
sands of years later Columbus and the succeeding ex- 
plorers surprised true American cultures that in many 
respects were as advanced as portions of the white 
world which they had left behind them. In the early 
accounts of the first white men who came to the two 
Americas, and from the remains that Indians have 
left, we are able to reconstruct a very satisfactory pic- 
ture of conditions at the time of the discovery, and 
we are able to look a short distance into the past. 
Beyond this, America’s past is just as nebulous as 
that of the world before 3000 or 4000 B.c. 

The prologue to the first copper-mining in North 
America was performed during the great ice age sev- 
eral hundred thousands of years ago. The ice-sheet, 
creeping down from the north, tore many masses of 
copper from the beds in which they had been deposited 
by geologic processes and, dragging them southward, 
spread them over the country and mixed them with 
débris. The glacier not only mined but transported 
close to the eventual places of use part of the same 
deposit of native copper which to-day furnishes a 
large part of the world’s supply. It was the famous 
Lake Superior deposits that were thus naturally pre- 
pared for the use of the North American Indians. 

It is probable that the way in which the Indians 


28 THE STORY OF COPPER 


came to use copper is the closest actual approach to 
the imagined story that appears at the beginning of 
this chapter. Over an area greater than seventy thou- 
sand square miles south of Lake Superior nuggets of 
drift copper had been spread. An Indian, searching 
for stone suitable for arrow-head making, tried the 
copper as a substitute material, liked it, and then 
looked for more. The treasuring of glacially distrib- 
uted metal led to the discovery that metal was also 
to be found in crevices of rocks, and undoubtedly it 
was not long before it was established that a small 
area near Lake Superior was richest in the metal. 
This became the center of the greatest industrial 
achievement of the North American Indian. Until a 
very recent time the mining pits excavated by the 
Indians and tens of thousands of stone boulder sledges 
used by them as mining tools still remained in parts 
of that region as memorials to aboriginal industry. 
In some cases such large masses of copper were en- 
countered that the Indians could handle or utilize them 
only with difficulty. Some of these large chunks of 
metal were unearthed and moved some distance from 
the mining pit, only to be abandoned until white men 
claimed them. The most famous of these, though by 
no means the largest, is perhaps the Ontonagon boul- 
der that was found on the bank of the Ontonagon 
River by early explorers. Indian hands had removed 
this four-ton mass about two miles from the outcrop 
of the lode which it came from; and in 1843, at the 
time of the beginning of the modern exploitation of 
the district, it was removed with much effort to the 
National Museum at Washington, where it now rests. 


KEY TO CIVILIZATION 29 


Native copper is also found in small quantities in 
Virginia, North Carolina, Tennessee, Arizona, New 
Mexico, Alaska, Mexico, and Nova Scotia; and while 
the natives may have used these deposits, most of their 
copper came from the Lake Superior workings. 
Copper was doubtless treated ‘like stone when the 
Indians first found it, but finally the malleability of 
the metal must have caused them to shape their im- 
plements by hammering instead of pecking. Copper 
tools and weapons were first modeled after those of 
stone, but finally the celts, hatchets, awls, knives, drills, 
and spear-heads changed in form so as better to util- 
ize the qualities of the metal. The pretty red color 
_ of copper and the high polish that they could give it 
delighted the barbarians’ eyes, and the metal had a 
high value for this reason alone. There is some evi- 
dence that a few tribes in North America practised 
casting to a limited degree, but wonderful results were 
accomplished by hammering, grinding, and perhaps by 
annealing. Thin sheets of metal were made by labori- 
ous hammering with stone implements, and the high- 
est skill in sheet-copper work is exhibited in intricate 
repoussé designs found in burial-mounds in Illinois, 
Ohio, Georgia, and Florida. Even copper-plating was 
practised by the aborigines. But instead of using 
electricity to deposit the metal, they covered jaw-bones 
of wolves, stone, shell, bone, wood, and other objects 
with thin sheets of copper. We may thank copper for 
preserving for us some of the rare examples of ancient 
Indian cloth and other objects that have usually de- 
cayed away. When copper beads and ornaments were 
worn, their salts sometimes impregnated the fibers and 


eo 


0 


B. C. 
8000— 


7000— 


6000— 


5000— 


4000— 


3000— 


2000— 


Europe 


THE STORY OF COPPER 


HISTORICAL TABLE OF COPPER’S USE BY MAN 


Man in north- 
ern Europe may 
have trod labo- 
riously in early 
steps taken by 
southern man 


Knowledge of 
copper and 
bronze spread 
slowly over 
Troy, Greece, 
Sicily, central 
Europe, France, 
Spain, Britain. 


and Scandina- 
via 


Egypt and Meso- 


potamia 


Copper used 
like malleable 
stone— metallic 
age dawns 


Casting copper 
discovered; cop- 
per reduced 
from oxide ores 
by smelting 


reduced 
and 


Tin 
from ores 
bronze made 


3700—Date of 
oldest piece of 
bronze yet 
known, found 
in Egyptian 
pyramid 


Bronze and cop- 
per in  abun- 
dant use 


Asia 


Did metallurgy 


come from 
China ? 
2500 — First 


mention of cop- 
per in Chinese 
literature (Shu- 
King) 


Bronze and cop- 
per used in 
China;  north- 
ern India in 
copper age; 
southern India 
passed directly 
from stone to 
iron age 


America 


America _ prob- 
ably received be- 
ginnings of hu- 
man _ habitation 
from Asia 


KEY TO CIVILIZATION dl 


Europe Egypt and Meso- Asia America 
potamia 
1000— Brass made by 
cementation of 
copper and cal- 
amine; sulphide 
ores smelted for 
copper; blue 
and green yit- 
riol made 


Christian 
Brac Use of native 


A.D. copper in North 
America and 
bronze in South 
America  devel- 
oped slowly un- 
til Columbus 
and other. ex: 
plorers arrived 


1000— 
1200 — Copper 
refined by ox- 
idation and pol- 
ing ° 
1492 — America 
1550 — Copper discovered 
ores roasted be- 
fore smelting 


Zak; t This small space represents one hundred years; the modern electric age, made 
possible by copper, occupies only half of this, at the most. ‘ 
The chronology is only approximate and may be modified by later discoveries. 
Africa, except Egypt and the northern part, had no copper or bronze age. 
Even remains of the Neolithic age are hard to find; Africa has been in the iron 
age since very early times. 


poisoned the organic agencies that threaten to disin- 
tegrate them. ; 

Thus we can see that learning to use metal was a 
long and sometimes a discouraging process for man. 
It may have taken a millennium for man to distinguish 
between stone and copper; in the hundred years just 
past a wonderfully rapid moving age of invention has 
remodeled the face of the earth. Man’s bronze key to 
civilization had slowly to unlock the future in different 
parts of the world at different times; to-day a new 
development in science is heralded around the world 
on copper cables, and virtually all of humanity must 
plunge into a new era together. 


CHAPTER II 
THE GENESIS OF COPPER 


In the beginning, perhaps, all matter was the same. 
There was no copper. Clouds of stuff, many, many 
times less dense than our earthly clouds of to-day, 
floated aimless through universal space, which was and 
still is cold, lifeless, and void. By processes that our 
astronomers are only now beginning to understand, 
nebule were converted into giant stars, like Betel- 
geuze, deep red, larger than our whole solar system 
but still much less dense than our star, the sun; then 
after countless eons these became whiter stars, and 
later they cooled to red again. In some rare cases at 
some auspicious time a few of these stars unburdened 
themselves of part of their substance and formed a 
circling, dependent company of planets. One of these 
—and, in fact, the only one that we are sure does 
exist—is the solar system of which our earth is one of 
the members. 

What is copper metal now may have been some- 
thing else in the beginning. Why we think this was so 
is another story, which will be told later. After 
more countless eons one of these revolving planets, our 
earth, arrived at the point in earthly evolution when 
some of the elements that had been formed during 


the ages of stellar evolution were ready to separate 
32 


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Courtesy of the U. S. National Museum 


CHALCOPYRITE ORE 


The rock is a piece of chalcopyrite ore, and the blocks show the quantities 
of copper, iron, and sulphur contained in it. Chalcopyrite is the color of gold. 
This mineral is a double sulphide of copper and iron, and contains 34.6 per cent 
copper, 30.5 per cent iron, and 34.9 per cent sulphur. The chunk of ore in the 
picture weighs 12 Ibs. 10 oz. The block of iron at the top weighs 3 lbs. 15 oz., the 


block of copper in the middle weighs 4 lbs. 4 oz., and the block of sulphur at the 
bottom weighs 4 lbs. 7 oz. 


THE GENESIS OF COPPER 33 


out from the common mass of matter and isolate them- 
selves. This time came when the earth cooled down. 
The surface began to look somewhat as it does now 
in places, and there began the series of events re- 
sulting in the segregation of copper and other miner- 
als, seemingly for man’s particular benefit. By per- 
sonal inspection, man knows only an infinitesimal part 
of the universe. He is beginning to be acquainted with 
the surface of the land fairly well, although there 
are still vast areas that he has only scratched. The 
great expanse of the ocean floor is a wild land for fu- 
ture explorers. In only a few places has man drilled 
into the interior of the earth, and below a mile and 
- a half downward the inside of the eight-thousand-mile 
ball on which we live is entirely unknown. The great- 
est upward height reached by him is a bare five miles, 
and beyond twenty miles even the thinnest trace of 
earthly atmosphere begins to disappear. Despite its 
apparent minuteness, the surface of our earth is all 
that we have to live on, and most of us consider it quite 
enough. All the copper we can hope to have and use 
exists on it or within a mile of it, and we must make 
the best of it. In the center of the earth there may be 
many cubic miles of copper, but why should we even 
think about it just now? It is true that this earth of 
ours receives an importation now and then in the 
form of meteorites, but these are not frequent enough 
to keep our museums well supplied, and careful chemi- 
cal analysis shows that they contain only about one 
hundredth of 1 per cent. of copper. If we look at a 
table showing the average composition of the rocks 
of the earth’s crust as determined by many chemi- 


34 THE STORY OF COPPER 


cal analyses of rocks, we see copper in a decidedly 
subordinate place. It ranks twenty-fourth, sand- 
wiched between lithium and cerium. Above it, and 
more abundant, we see aluminum, iron, magnesium, 
chromium, nickel, and other metallic elements. The 
crust of the earth has larger amounts of all these ele- 
ments than copper; only two thousandths of 1 per 
cent. of the crust is copper, or, saying it differently, 
there would be only one ton of copper in fifty thou- 
sand tons of earth’s crust if we could assume that all 
copper were evenly distributed. Yet because nature 
has placed the total amount of copper in relatively 
easy form for man’s exploitation, there are to-day 
relatively large amounts of copper available for use. 

Now that we know how much copper there is, it is 
appropriate that we be formally introduced to the 
copper mineral family, which is responsible for the 
copper of the world. Some of them we have already 
met informally in the first chapter, and we shall be- 
come intimately acquainted with all of them as our 
story goes on. | 

First comes the bachelor of the copper family: na- 
tive or free copper. It is quite the purest and most 
solitary member; it is the metal itself. In size, native 
copper occurs from small grains to great masses 
several hundred tons in weight, and it may also be 
found in threads and wires and in distorted crystals 
and twisted groups. It is not a very hard substance, 
but the finger nail is too soft to scratch native copper. 
Native copper is found in twenty-seven States of the 
Union; in the upper part of copper deposits at the 


THE GENESIS OF COPPER 30 


Coro Coro Mines in Bolivia; the Faroe Islands; 
Atacama, Chile; and Wallaroo, South Australia; with 
other deposits elsewhere. But it occurs native in 
quantity principally in the Lake Superior district, 
where the Indians worked it long before the white man 
arrived. 

The greatest and most important offshoot of the 
copper family came about through the intermarriage 
of sulphur and copper. The sulphur family is rather 
a troublesome group, and when man divorces these two 
elements so that he may utilize the copper alone he 
has more difficulty in performing the separation than 
he does when copper is married to some milder ele- 
ment such as oxygen. Sulphur, though, does its share 
in the work of the world, as after the divorce it is often 
put into service for the manufacture of sulphuric acid. 

Next let us become acquainted with covellite, other- 
wise known as indigo copper. According to its an- 
cestry it is about two thirds copper and one third 
sulphur. In complexion it is a very dark indigo-blue, 
and it is considered by many to be the most beautiful 
of all the copper mineral family. As an ore, however, 
it is rare, although it is produced in large quantities 
from one mine at Butte, Montana. In the chemical 
world covellite is known as cupric sulphide, and the 
name is written CuS in the abbreviated language of 
chemists. 

The other member of the copper sulphide family is 
the most important copper ore in America. Its name 
is chalcocite,—otherwise copper glance and vitreous 
copper,—and its lineage shows 79.8 per cent. of copper 


36 THE STORY OF COPPER 


and 20.2 per cent. of sulphur. Its abbreviated name 
is Cu,S8. Chalcocite is lead-gray and often has a coat 
of blue or green tarnish. Often large masses of it 
have been found, and in the Butte Mine in Montana 
and the Bonanza Mine, Copper River, Alaska, veins 
occur whose measurement is more than twenty feet 
across. 

A member of the family that often lives closely as- 
sociated with chaleocite is bornite. An additional ele- 
ment has contributed to the make-up of bornite, and 
if we look into its ancestry we find 11.2 per cent. of 
iron, in addition to 63.8 per cent. of copper and 25.5 
per cent. of sulphur, or more simply expressed 
Cu;FeS, This mineral is also known by several 
other names: erubescite, purple copper, variegated 
copper, peacock copper, and horse-flesh copper. It 
gets these varied names because when first broken open 
it is of a peculiar red-brown color, which tarnishes to 
deep blue and purple tints, often variegated. Bornite 
is an important ore in many mines, notably in some of 
those at Butte, Montana, in Chile, in South Africa, in 
Tasmania, and in a few Australian mines. | 

Another of the family is chalcopyrite, which, judged 
by its appearance, might be Cresus himself. It has 
a true gold color, if you do not happen to see its fre- 
quent iridescent tarnish, and it looks genuine enough 
to fulfil your expectations and yield much gold. But 
it resembles its cousin, pyrite, or iron sulphide, which 
has earned the name of ‘‘fool’s gold,’’ and its color is 
better called brassy than gold. Instead of gold, chal- 
copyrite is made up of nearly equal amounts of copper, 
a baser metal, iron, and sulphur; to be exact, the di- 


THE GENESIS OF COPPER 3” 


vision is 34.5 per cent. copper, 30.5 per cent. iron, 35.0 
per cent. sulphur. It is also known as copper pyrite 
and yellow copper ore. This mineral, whose code 
name is CuleSs, is often regarded as the mineral from 
which many other copper minerals are descended; 
and, in addition to its primary nature, it is geo- 
graphically the most common copper mineral of the 
ore deposits of the world, though not the prevailing 
mineral in the greatest producing mines in this coun- 
try. . 

The sulphide branch of the copper family has inter- 
married with still other elements on the metallic side. 
When this occurred with arsenic, enargite resulted; 
and when antimony was the addition, the new mineral 
was tetrahedrite. i 

Until a few years ago enargite, known in chemical 
circles as sulpharsenide of copper, or Cu,AsS,, was 
not considered of great commercial importance, but it 
has since been found that it is one of the great ores of 
the world, yielding probably 3 per cent. of the copper. 
One third of the ore at Butte, Montana, is enargite. 
This mineral is grayish-black and brittle, and the fact 
that it contains 19.1 per cent. arsenic caused some per- 
sons to scorn it before electrolytic refining provided a 
method of purifying it. Sometimes, in some kinds 
of enargite, zinc or iron will be found replacing part 
of the copper, and the arsenic may have antimony sub- 
stituted for it in part. 

When antimony, sulphur, and copper combine, tetra- 
hedrite, otherwise gray copper ore, is formed. Itis a 
variable mineral, and sometimes we find that the cop- 
per is partly replaced by iron, zinc, lead, mercury, or 


38 THE STORY OF COPPER 


silver, while arsenic substitutes for antimony. As its 
nickname implies, it is a light steel-gray to iron-black 
mineral; and though it is one of the most frequent min- 
erals in copper deposits it is not an important ore, as 
it seldom occurs in large quantities. Wherever it oc- 
curs it usually carries valuable silver along with it. 

Next comes the airy branch of the family, formed of 
a combination of oxygen and copper. The evolution 
of this branch is usually through a divorce of sulphur 
from copper with a subsequent marriage of copper to 
oxygen. Cuprite, Cu,O, also known by the names of 
red oxide of copper and ruby copper ore, is usually 
some shade of red or brown, and it virtually always oc- 
curs with the carbonates, malachite and azurite, to 
whom we shall be introduced shortly. In the early 
development of copper deposits cuprite was an import- 
ant mineral because it was at the top of the deposits, 
but now it has had to relinquish the most important 
place in production to the sulphide members of the 
copper family. 

The carbonate family, closely related to the oxide 
branch, is a flashy group, which does a large amount 
of painting. Most important is malachite, whose color 
is green; but, occurring close to malachite, the blue 
mineral azurite will often be found. Malachite, which 
has the long code of Cu,(OH).CO; is the most im- 
portant oxidized ore of copper, and it is not only use- 
ful but ornamental. In the Russian mines of the 
Ural district are obtained large and solid masses 
from which vases and other works of art are eut. You 
can buy copper ore in a jewelry store in your city, if 
you know what to ask for or can pick it out from the 


THE GENESIS OF COPPER 39 


array of semi-precious stones. Many of the brooches 
and dinner rings containing green stones, often banded 
with concentric rings, are set with nothing more than 
the copper ore, malachite. This ore is a little less than 
two thirds copper, but it often dissipates its strength 
and color so much that many of the wide-spread de- 
posits cannot be mined on a paying basis. It covers 
much ground, and a little of it will stain a very large 
amount of rock. Worst of all, it is deceitful, as it 
colors thin and worthless incrustations or nodules of 
worthless material and disguises them as valuable ore. 
Azurite is malachite’s companion, and, like it, is a car- 
bonate, descended, through the union of water, from 
_ decomposing members of the sulphide family coming 
into contact with limestone. Chemically it is known 
as Cu;(OH).(CO;),.. The light azure too deep rich 
blue of azurite contrasts well with malachite’s green, 
and in some localities such as Morenci, Arizona, and 
Laurium, Greece, nature has been thoughtful enough 
to form them into concentric bands so that we may 
easily admire the beautiful comparison. Often it 
shows off its beauty in splendid crystals, and it is bet- 
ter known for its beauty than for its producing value 
as an ore. 

Chrysocolla is another highly colored ore of copper, 
and it is the single important representative of the cop- 
per silicate family. If we investigate its composition 
we find 45.2 parts of copper oxide, 34.3 parts of silica, 
and 20.5 parts of water. Its peculiarity is that it 
never occurs in crystals, and you may mistake its im- 
pure earthy blue and green for a piece of kaolin col- 
ored by copper. Often it will be seen with an opal-like 


40 THE STORY OF COPPHR 


or enamel-like structure. Its most important occur- 
rence is in Arizona, where large areas are underlaid 
by it, and it is also found in Chile and Belgian Congo. 

I shall list the other but minor members of the cop- 
per mineral family, mentioning their closest relatives 
among the important copper minerals. Famatinite 
is closely related to enargite, the only difference being 
that famatinite has antimony as a constituent, while 
enargite has arsenic. Tenorite, better known as mela- 
conite or black oxide of copper, is a member of the 
oxide family similarly to euprite, but its code name is 
CuO, and it is black. It is not very important, al- 
though it has the distinction of being formed at the 
present time by the vapors from the voleano Vesuvius. 
When blue vitriol or copper sulphate occurs as a min- 
eral it is known as chaleanthite. Like the artificial 
product it is blue and glassy, and if you tasted it you 
would find it disagreeably metallic. This is an ore 
that mine water sometimes leaches out and saves man 
the trouble of both the mining and the preliminary 
treatment. Brochantite is another sulphate mineral. 
Chlorine’s intermixture with the copper family has 
resulted in a basic chloride called atacamite, and in 
Chile and South Australia, this is an ore of some im- 
portance. 

It has been estimated that chalcocite and chalcopy- 
rite are together responsible for about three quarters 
of the world’s production; chalcocite probably pro- 
duces half of the world’s copper alone. Native cop- 
per, chiefly from the Michigan region, is responsible 
for about 6 per cent. of the world total and, because of 
the large masses at Butte, enargite contributes about 


THE GENESIS OF COPPER 41 


3 percent. The rest of the production comes largely 
from oxide ores, with the other minerals doing their 
small bit. 

Man is interested in the elements with which copper 
has intermarried, not only because through science 
and experience he has discovered that certain ores are > 
usually found under certain conditions, but also be- 
cause he has to divorce copper from the combining 
elements before he can use this metal. For the second 
reason, also, he is interested in the gangue that copper 
minerals associate themselves with. By the term 
‘‘rangue’’ the geologist indicates the rocks and min- 
erals that surround copper ore. These rocks and min- 
erals may be very interesting and, in their proper 
place, useful, but when they prevent a great density of 
copper population they are gangue and nothing more. 
Some kinds of gangues are less troublesome than 
others, and if they are present in the proper propor- 
tion with the proper members of the copper mineral 
family they may even aid in the process of getting rid 
of themselves. Quartz, the common mineral, is the 
commonest gangue of copper ores. Calcite, the car- 
bonate of lime, and siderite, the carbonate of iron, 
are also common in some deposits but are plentiful in 
only a few of the greatest mines of the world. Very 
often the gangue is not composed of these relatively 
pure minerals but is earthy and a highly altered 
country rock. Barite, rhodochrosite, and fluorite are 
other troublesome neighbors of copper ore that man 
must remove before copper can be obtained. 

Pyrite, or iron sulphide, is also a common companion 
of copper minerals, particularly the sulphides, but, as 


42 THE STORY OF COPPER 


we shall see later, it often provides fuel that results in 
the divorce of copper and sulphur. Iron oxide, or 
hematite, and other metallic oxides also often form the 
gangue of copper minerals. | 

There are some metallic minerals that are deleterious 
in copper ores, although if they were alone they would 
be prized as a source of other metals. Zine and copper 
do not get along very well in mineral form, although 
after they achieve the metallic state they often form a 
successful partnership under the name of brass. 
Sphalerite, zinc sulphide, is considered the most ob- 
noxious of such harmful minerals, and to discourage it 
‘ smelters have established a ‘‘zine penalty’’ which takes 
the form of a fine if the sphalerite in copper ore 
is over 10 per cent. Bismuth, arsenic, antimony, tel- 
lurium, and selenium minerals are very objection- 
able associates of copper ores, but electrolytic refin- 
ing of copper eliminates them and the trouble they 
cause. 

The past history of the copper ores is nearly as 
mixed and difficult to untangle as human genealogies. 
So many things have happened in the geologic ages of 
the earth to complicate the lineage of even one particu- 
lar spot rich in copper that it often takes years for 
geologists to find to their satisfaction the probable 
descent. Each kind of copper deposit has character- 
istics all its own, and though the types of copper de- 
posits have not been separated very distinctly, their 
genesis is probably better known than that of the dif- 
ferent races of the human kind. Complicated and un- 
certain as the past of copper may be, it is useful to 
make an attempt at unraveling it, because through 


THE GENESIS OF COPPER 43 


knowing its past, man can better determine the pres- 
ent location of copper. 

Gaze at the ocean, visit a voleano, or admire a hot 
spring. If you do, it is likely that you are unknow- 
ingly witnessing the most recent creation of copper 
deposits. Sad to say, these new communities of cop 
per deposits, while ‘‘nouveau,’’ are not ‘‘riche,’’ and 
no great exploitable deposits are being formed in this 
way. Copper salts and copper oxide are deposited by 
voleaniec vapors and: gases in the rifts about active 
voleanoes. Several vein-forming hot springs are 
known, and one in which copper minerals are being de- 
posited is at Boulder Hot Springs, Montana. Some- 
times cold copper-bearing waters are found, but these 
can usually be traced to oxidizing ore deposits. Cop- 
per minerals deposited in the organic muds of sea la- 
goons, while well-known, are a scientific curiosity 
rather than examples of how the workable ores used 
to-day were laid down. Nature at work to-day con- 
centrating copper gives us a chance to see a small part 
of the geological drama that resulted in the ore de- 
posits that man now works. 

If we trace back the genealogy of all the copper de- 
posits of the world, even those that are being formed 
to-day, we shall find that they originated in the hot, 
molten material in the interior of the earth. First it 
was the magma itself, as this molten material of the 
earth is called, that carried the copper up to the crust 
of the earth; and when the magma consolidated and 
intruded itself into the rocks of the crust, the copper 
as such or in chemical combination, either stayed with 
it diffused throughout the mass or in a few cases con- 


Af THE STORY OF COPPER 


veniently separated itself out. The cooling and erys- 
tallizing rocks gave off aqueous solutions that also 
carried copper upward to be deposited in cracks, and 
when things cooled down a bit boiling water, emanat- 
ing from deep molten material, took up the work of 
transporting the copper to the zone where man can 
use it. Finally hot springs, just as they are doing 
now, deposited copper from their waters, which in 
many cases were a mixture of water from the magma 
and that which had fallen as rain from the atmosphere 
and seeped down into the heated regions. 

Nature’s action in forming ore deposits is only the 
first step in a process of concentration which man 
takes up and carries to completion when he mines, 
smelts, and refines the naturally concentrated copper 
minerals called ore. But nature has often tried many 
methods of enriching a single ore deposit as the geo- 
logic eras have passed by, and for that reason a de- 
scription of her concentrating process is harder to 
write than an explanation of man’s more modern and 
more logical methods. 

If copper can be separated from the original molten 
material or magma, that would seem to be the easiest 
method of forming copper ore. This has happened, 
but rarely have workable deposits been formed by this 
method. The molten magma is composed of various 
compounds, among them the sulphides of copper and 
iron, pyrite, pyrrhotite, and chalcopyrite. These me- 
tallic minerals need more heat to remain molten than 
the other parts of the molten rock, and when the cool- — 
ing process starts, they are the first to become solid. 
Sometimes the particles that solidify first come to- | 


THE GENESIS OF COPPER 45 


gether in masses that become workable ore. Another 
theory explaining how copper minerals are deposited 
from the molten magma is that it is due to the fact that 
the sulphur loves copper better than any other metal. 
Sulphurous gases escaping through the still molten 
rock choose copper and change it into its sulphide. 
These copper minerals concentrate themselves along 
the contact of the magma with the surrounding rock. 
It was in this way, geologists believe, that the deposits 
at Sudbury, Ontario, the only workable American de- 
posits of magmatic origin, were formed. 

By far the largest part of the copper in the world is 
carried upward and laid down in rock by the processes 
. that the geologist has disguised under the terms of 
‘‘contact metamorphism’’ and replacement or by an- 
cient processes corresponding to the present-day de- 
posits by hot springs. 

The great and valuable deposits of Clifton-Morenci, 
Bingham Canon, and Bisbee in this country, and those 
of the Kristiania region in Norway are classed by 
geologists under the heading of contact metamorphism 
deposits. Here is the story of the genesis of these 
great copper deposits as they tell it. A mass of mol- 
ten, igneous rock, part lime-soda feldspar and part 
potash feldspar, pushed its way up into limestones and 
shales. The gases and solutions given off by the cool- 
ing and crystallization of this magma, together with 
the heat of the molten rock itself, changed the lime- 
stones to a compact, impervious rock. It created and 
left behind garnets and other minerals that the geolo- 
gist has learned to use as a sign of these changes in 
the structure of the rock which are called metamor- 


46 THE STORY OF COPPER 


phism. Pyrite, rich in copper, was also deposited. 
As the molten intruding rock cooled down, it fractured, 
sheeted, and crackled because of the cooling stresses, 
or possibly there were earth movements caused by the 
voleanic action. The cracks and fractures allowed 
more of the gases and solutions from the lower molten 
rock to deposit their burden of metallic compounds in 
the breaks of limestone and in the shale, and in some 
cases the solutions penetrated parts of the now cold 
and solid upper magma and filled it with mineral. 
Such copper storehouses as that at Butte, Montana, 
are believed to have had their veins filled by a later 
phase of the igneous activity. When molten rock it- 
self and its gases no longer rose from the interior, hot 
waters took up the task of elevating copper to near the 
surface. In part the water probably came from the 
interior of the earth, but some of the rain falling on 
the surface above must have seeped down into the 
depths of the earth, bringing with it some of the copper 
and other minerals carried up by the gases and the 
magma as a part of earlier ore depositing activity. 
These mixed waters were promptly sent upward, and, 
from the appearance of the deposits at different levels, 
geologists have guessed how and when they relieved 
themselves of their burdens of copper compounds. 
In the deeper parts of the earth the waters were under 
great pressures that allowed them to take into solu- 
tion compounds that we usually call difficultly solu- 
ble in water. As the upward movement progressed 
the pressure decreased and the waters could no longer 
hold the _ difficultly dissolved compounds. They 
dropped them, and an ore deposit of that particular 


THE GENESIS OF COPPER 47 


material was formed. This process of gradually get- 
ting rid of their metallic burdens continued as the 
pressure decreased and the waters increased their 
proximity to the surface of the ground. When at last 
daylight was reached, the waters had been able to hold 
on to only the easily soluble substances, such as the 
alkaline carbonates and the chlorides and silica. Be- 
low in veins the valuable copper sulphides had been 
safely deposited for man to draw upon. 

The native copper deposits of the Lake Superior 
region are also believed to be the result of some phase 
of igneous activity. In this case, because of unusual 
conditions, chemical and physical, copper was de- 
- posited directly as native copper rather than as an ore. 

The famous Calumet and Hecla and Tamarack mines 
work the beds where the copper was placed in conglom- 
erate as small particles in the cement between the 
pebbles, and one third of the Michigan copper is ob- 
tained from this type of bed. A dozen big mines work 
the amygdaloid copper-bearing beds. ‘‘Amygdaloid’’ 
means ‘‘almond-shaped,’’ and the beds get this name 
because the copper occurs in the blow-holes of this 
form that were left by steam during the cooling of the 
lava. With the copper, native silver is also found in 
small quantities. Early in the history of the Lake 
Superior copper-mines, veins that are now of little 
economic importance produced most of the copper. In 
these cracks, formed by filling with copper, or by cop- 
per replacing some other elements and taking its form, 
the famous masses of native copper weighing up to five 
hundred tons were found. 

Whether copper has been laid down in the sediments 


48 THE STORY OF COPPER 


of seas is another question regarding copper’s gene- 
alogy that geologists are attempting to answer. They 
are trying to decide whether such deposits as occur 
at Mansfeld, Germany, in sedimentary rocks were cre- 
ated in the same way as the surrounding rocks or 
whether they had a different origin. 

Nature is not usually so thoughtful and generous as 


So 


she 


b) 


CONGLOMERATE COPPER SANDSTONE 


After T. A. Rickard 


DIAGRAM SHOWING HOW NATIVE COPPER OCCURS IN CONGLOM- 
ERATE LODES IN MICHIGAN DEPOSITS 


in the case of the Michigan native copper deposits, 
where the copper itself attracted men’s attention. 
Often she hides her wealth of copper under a cap of 
worthless, rusty material. But even when this hap- 
pens, nature, in endeavoring to bury her copper, has 
enriched the lower ores and made them more accept- 
able for man’s use. At Butte, Montana; Rio Tinto, 
Spain; Ducktown, Tennessee; and Clifton, Arizona, 
this natural concentration of the deposit has occurred 


THE GENESIS OF COPPER 49 


through the action of the weather on the ores near the 
surface. The primary ores such as pyrite, pyrrhotite, 
and chalcopyrite are changed by the oxygen of the air 
and rain-water; and when much iron sulphide is 
present, soluble copper and iron sulphates result. The 
descending water carries these compounds to the un- 
affected ore just below, and there they are precipitated 


SURFACE 


LIMONITE GOSSAN 


ZB Oxides and = carbon- 
ates (559 to 88%) 


Zone of secondary sulphides 
Copper glance area 
Bornite and chalcopyrite 


Primary ores,  chal- 
copyrite (34.8% cu.) 
with pyrite, etc. 


From Weed’s ‘‘Copper Mines of the World’’ 


DIAGRAM SHOWING HOW NATURE HIDES A WEALTH OF CONCEN. 
TRATED COPPER ORES UNDER A LEAN CAPPING OF WORTHLESS 
IRON ORE 


out of solution. This creates a zone of very rich ore 
between the worthless, leached-out ‘‘gossan’’ or iron 
cap, as it is called, and the unchanged original ore 
further down. In some deposits the lower part of the 
weathered zone often shows a wealth of so-called oxi- 
dized ores of copper. These enriched areas are also 
due to the downward percolating waters that have 
stolen the riches of the upper part of the vein. At 
Butte it was only the silver in the gossan that attracted 


50 THE STORY OF COPPER 


the miners and caused them to reach the rich copper 
glance ore. Many veins in the oxidized zone did not 
show even a copper stain to indicate that rich second- 
ary ore lay just below. 

How long have the various copper minerals been 
where man has found them? Most of the copper de- 
posits of the world are comparatively young, as geolo- 
gic ages go. Though, as we have heard before, all 
copper came from the molten material that formed the 
earth, it was not until the evolution of life on this 
earth had been in operation hundreds of thousands of 
years that the large producing copper deposits of the 
United States were formed. The age of fishes had 
passed, and birds, mammals, hard wood trees, and 
palms had appeared before the creation of the deposits 
that now provide four fifths of the copper of this 
country. During the geologic time known as ‘‘Ter- 
tiary’’ the great copper deposits of Butte, Montana; 
Morenci, Arizona; Santa Rita, New Mexico; Bingham, ~ 
Frisco, and Tintic, Utah; and other places were 
formed. Although the end of the Tertiary period 
marks the first appearance of man in the earth’s ac- 
tivity and despite the fact that it is a remote date 
from the point of view of human evolution, it is a very 
recent date in the history of the formation of the crust 
of the earth. With the beginning of the Tertiary 
period an epoch of igneous activity was begun in 
America which has continued, with occasional inter- 
ruptions, from that time to the present. Because 
copper’s original source is the igneous material flow- 
ing out from the center of the earth, the copper de- 
posits are largely to be found associated with the great 


THE GENESIS OF COPPER ol 


mountain ranges of to-day that were produced by this 
recent igneous activity. Otherwise copper is found 
in the old or planed-down ranges where stumps of 
mountains alone remain. A little older than the Ter- 
tiary deposits are those at Shasta County, California; 
Foot-hills belt, California; Ely, Nevada; Yerington, 
Nevada; Alaska; Bisbee, Globe, and Ray, Arizona; and 
others which occurred in the Mesozoic era. These 
mines in 1913 contributed about 36 per cent. of the 
copper produced in the United States. But there are 
copper deposits that can claim a genesis before that of 
life on the earth. Those of Michigan; Jerome, Ari- 
zona; and Encampment, Wyoming, are credited with 
creation in Pre-Cambrian times. The Ducktown, T'en- 
nessee, and other Appalachian deposits, however, date 
from the Paleozoic era and therefore antedate all 
the other American deposits except those of the Pre- 
Cambrian. Geologists guess that Pre-Cambrian times 
were at least two hundred and fifty million years ago, 
but that they may have been as much as a billion years 
in the past. : 

I am now going to give you copper’s secret signs, 
which can be answered by only the copper family. 
With them you will be able to tell whether a mineral 
claiming to have copper in its veins is telling the truth; 
you will be able to expose any impostors claiming cop- 
per’s rights. 

Submit a copper compound to the test of fire by 
placing it in a flame, and it will respond by giving the 
flame an emerald-green to azure-blue coloration, de- 
pending on the compound. If a bead of borax is made 
and dipped into a copper compound, the bead will be 


o2 THE STORY OF COPPER 


colored green when in a hot oxidizing blow-pipe flame 
and blue when it cools. When a copper salt is in solu- 
tion, if ammonia is added, a characteristic blue color- 
ation is produced. Another sign that copper will an- 
swer even though only one part in 500,000 parts of 
water is present consists of adding potassium ferro- 
cyanide to a copper solution and obtaining a brown 
color, or precipitate. 


CHAPTER III 
THE HARTH’S HERITAGE OF COPPER 


If some one asked you, ‘‘How much copper does the 
earth contain?’’ you might remember the figures in 
the last chapter and be tempted to multiply the weight 
of the earth by .00002 and obtain some 120,000,000,000- 
000,000 tons as the astonishing answer. But this 
would be unprofitable meaningless labor, as man has a 
chance of extracting from the earth and turning to his 
use only a very small part of the copper in the crust 
of the earth, and he does not know there is any deeper 
down. 

Before we find out how much copper the world has 
to spend, let us see how much has been taken from the 
earth and used. For thousands of years the copper 
resources of the world have been exploited, but in the 
last half-century, particularly the last two decades, 
since demand for copper for use in the electrical and 
other modern industries has been great, the production 
has surpassed all previous amounts many times. 

More than a million metric tons a year, or over 
_ 2,200,000,000 pounds, is the average amount of copper 
claimed from the earth during the ten years ending 
with 1920. The United States is responsible for a little 
less than two thirds of this production, and at no time 


has even its closest rival produced more than a tenth 
53 


o4 THE STORY OF COPPER 


OCEAN 
GREENLANB 


ARCTIC 


NORTH 
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NORTH PACIFIC 
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0, 
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SOUTH 
s 
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eo 
SOUTH PACIFIC 3 


4 ee OCEAN 
A 


HERITAGE OF COPPER 


EuROPE hd 


ay) 


e 
; \J ; Aah Some hs ( 
ay eMANSFELD 2% re h 


SOUTH 


JNOIAN OCEAN 
°° 


ATLANTIC 


OCEAN 


WORLD PRODUCTION OF COPPER 


EXPLANATION 
A SMALL DOT REPRESENTS ONE PERCENT OR LESS OF 
THE WORLD?S PRODUCTION IN 19713. 
(IORE PRODUCTIVE LOCALITIES ARE /NDICATED 8Y LARGER 
DOTS, WITH FIGURES GIVEN WHICH SHOW THE PERCENTAGE OF 
THE WORLD’S TOTAL PRODUCED AT THAT PLACE. 


Yh oe wees yer 


NOATA 


PACIFIC 


OCEAN 


06 THE STORY OF COPPER 


of the copper of the world. Chile, Japan, and Mexico 
have at various times during the last decade been the 
second largest producing countries. 

There are given below the figures of the United 
States Geological Survey for world production in 1913, 


Wor.Lp’s PRopUCTION OF CoPPER IN METRIC TONS 


Country 1913 1918 
Austria-Hungary 4 TOO 2% teas 
England 428 182 
France io RI aie: Sl Pr 1,228 
Germany 49,400 35,000 1 
Italy 2,091 1,139 
Norway 2,741 2,856 
Portugal 5,800 1 4,000 1 
Russia 33,694 4,999 1 
Serbia GA00 8 Oakes 
Spain 31,248 45,104 
Sweden 4,215 2,956 
Turkey BOO os tires 

Total Europe 140,617 97,464 
Canada 34,916 53,873 
Cuba 3,400 1 13,300 1 
Mexico 52,800 1 70,223 
United States 555,422 865,705 
Total North America 646,538 1,003,101 
Argentina 100 2. eee 
Bolivia 900 8,422 
Chile 42,263 115,000 1 
Peru 27,776 44,414 
Venezuela. 7201 2,079 
Total South America 71,759 169,915 
Belgian Kongo » 7,530 1 20,238 
Namaqualand 2,500.8) ies 
Southern Rhodesia = —. 6) © 4 eee 2,952 
Union of South Africa 8,318 4,824 
Total Africa 18,348 - 28,014 
Japan 66,501 90,341 
Australia 45,647 39,315 
Grand Total 989,410 1,428,150 


(One metric ton equals 2204.6 pounds) 


1 Unofficial figures. 


— 


HERITAGE OF COPPER Oo” 


the pre-war normal year, and in 1918, which is the year 
when the climax of war production came. 

But 1918’s record production did not extend over 
into the next four years. Large stocks of copper ac- 
cumulated as soon as the war ended, and by 1920 world 
production dropped to about 834,700 metric tons, less 
_ than the total in 1913. Of this amount the United 
States produced 548,426 metric tons. The figures for 
1921 are even smaller, as the production in the United 
States was only 229,332 metric tons for the year. The 
year 1922 saw a revival to 432,800 tons, while the pro- 
duction for 1923, 671,400 metric tons, exceeded the 
production for 1913. 

Just how much copper has been freed from earthy 
bondage since that early day when the first native cop- 
per was used can hardly be estimated. Even at the 
beginning of the eighteenth century the world’s pro- 
duction of copper was probably not more than seven 
thousand tons a year, with Great Britain producing 
three quarters of this. One hundred years ago the 
mines of the United States, Chile, Mexico, Canada, 
South Africa, Australia, and Tasmania, which now 

produce about nine tenths of the copper of the world, 
were totally undeveloped. Not until the middle of the 
last century, when the Lake Superior mines were 
opened, did the production of copper reach large pro- 
portions. 

Copper has had the strange and happy experience of 
having two youths. From the dawn of history until 
the end of the medieval period it was the world’s most 
important metal. Then iron and steel usurped cop- 


08 THE STORY OF COPPER 


per’s place, and by the beginning of the nineteenth cen- 
tury ferrous products had attained such use and pro- 
duction that they almost totally eclipse copper. 
When Morse, Bell, and Edison turned to practical use 
the academic researches on electrical phenomena that 
earlier scientists had conducted, copper entered its 
rejuvenation. Its second life seems much more vigor- 
ous than its first. Even the most imaginative. scien- 
tist cannot foresee a formidable substitute for copper 
in the general electrical field. The earth must con- 
tinue to furnish red metal that will make possible the 
extension of the electrical age. 

Fortunately, geologists predict that the earth is 


20 eo 


1810-20 1630-40 1850-60 (I870~ 1890- 19090 1S1O~- {S20 


WORLD’S COPPER PRODUCTION BY DECADES, 1810-1920 


ready to furnish large amounts of copper, provided 
man is willing to expend the necessary energy. It is 
hard to estimate even approximately the amount of 
available copper that the earth contains. The geolo- 
gist and mining engineer compile and list what the 
copper companies call their ‘‘ore reserve,’’ but it is 
quite possible that the large producing mines of two 


HERITAGH OF COPPER o9 


or three decades hence are only partly explored 
at the present time. A few years in the future the 
waste piles of mine tailings may themselves be con- 
sidered as valuable as new diggings. Processes for 
the recovery of copper from ores have improved so 
rapidly that already some of the débris from former 
mining operations is being worked over for the small 
amount of metal it contains. In fact, the known supply 
of copper ore in the United States has been increased 
during the last few years, and it is probable that for 
several years mining and metallurgical methods have 
added to the reserve more available copper than 
was newly extracted during the same period. In 
some districts the copper made available in the tail- 
ings of earlier operations would go far toward equal- 
ling current production. Whether or not a large 
amount of copper is produced depends upon how much 
people are willing to pay for it. If the price of cop- 
per were twenty cents a pound, much more would be 
mined and smelted than if the price were thirteen 
cents. Whenever the price of copper rises, there is an 
addition to the amount of copper that the world can 
produce under the existing conditions. If the price 
drops, the world’s copper reserves must take a slump 
because of the new and less favorable conditions. It 
is similar to offering a man more money if he will work 
longer hours, or, in the other case, it is like reducing 
his pay. ; 

Yet the copper resources of the world are relatively 
limited. Experts have predicted that in twenty years, 
unless new deposits are found, we shall be confronted 


60 THE STORY OF COPPER 


with a shortage of copper similar to conditions before 
the discovery and development of the ‘‘porphyry”’ 
mines about 1900. At that time the supply of copper 
ore in the United States seemed extremely limited. 
In that case, improvements in mining and treatment 
of ore saved the situation and made it possible to work 
these low-grade porphyries, containing about 2 per 
cent. copper, in competition with ‘‘vein’’ mines carry- 
ing higher percentages of copper. These mines of a 
new type, it was then found, could be excavated with 
steam-shovels such as those that were used on the 
Mesabi iron range. Instead of being thousands of 
feet deep like vein mines they were only a hundred feet 
or so in vertical depth. The vein mines previously 
worked at Butte, in Michigan, and in the Clifton and 
Globe districts were only ten to forty feet wide and 
dipped steeply into the earth; the porphyries were 
thousands of feet long and often a thousand feet wide, 
lying comparatively flat and close to the surface of 
the ground. 

It is hard to say whether such a shortage will actu- 
ally occur. We can hope that better metallurgical 
methods and more prospecting will prevent its oc- 
currence, and at the same time see what copper ore 
reserves are reported at the present time. Figures 
on the copper laid up in Mother Earth’s subterranean 
vaults are not complete, as many companies do not 
make public their reserves. When looking over these 
figures, remember that the average annual world cop- 
per production for the last decade was about 2,200,- 
000,000 pounds. 


HERITAGE OF COPPER 61 


Estimates of the ore reserves of some of the mines 
are as follows: 


Mine Ore reserves, tons Per cent. copper Recoverable 

copper, pounds 
Andes Copper, Chile 138,890,509 1.498 3,330,000,000 
Braden Copper, Chile 264,510,000 2.26 9,655,000,000 
Chile Copper 688,629,889 2.12 25,500,000,000 
Chino Copper, Santa 

Rita, N. M. 105,385,461 1.53 2,580,000,000 
Inspiration, Globe, 

Ariz. 72,374,741 ae 1,380,000,000 
PpEOCUCL TA IGHER 9 ke ea a oie 490,000,000 
Miami, Globe, Ariz. 14,899,834 2.15 447,000,000 
Nevada Consolidated, 

Ely, Nev. 63,401,209 1.58 1,550,000,000 
New Cornelia, Ajo, Ariz. 65,000,000 1.45 1,495,000,000 
Ray Consolidated, Ray, 

Ariz. 82,652,220 2.068 2,734,000,000 
Utah Copper 362,910,100 1.35 7,840,000,000 


Data on the large vein mines are not available, 
but several years ago it was estimated that there 
were about 2,700,000,000 pounds of recoverable cop- 
per in the principal mines of the Lake Superior re- 
gion. 

Many of the developments that show large ore re- 
serves are of comparatively recent date. A few years 
ago the figures for the Chile Copper deposits were 
considerably lower. 

Changes have been made constantly in the copper 
reserves of the world during the last few years, 
largely because of the great African deposits that are 
being proved. The table showing world copper re- 
serves, as compiled by F. W. Paine and published in 
1920, has been upset somewhat. Recent reports from 


62 THE STORY OF COPPER 


the Katanga region in Belgian Kongo tell that there 
are 70,000,000 long tons of ore proved and under de- 
velopment, running 5.7 to 16.7 per cent. copper, and 
containing 10,080,000,000 pounds of metallic copper. 
Other estimates indicate that there may be 300,000,000 
tons of ore, which will eventually produce the immense 
total of 42,560,000,000 pounds of copper. These de- 
posits are in the interior of Africa and at present are 
hampered commercially by high transportation costs. 
Russia also contains valuable deposits which are cut 
off by present political conditions, and these will prob- 
ably produce 11,000,000,000 to 12,000,000,000 pounds of 
metallic copper. 

These recent estimates revise the statistics on the 
control of the world’s copper resources. Using the 
most conservative estimates on reserves, American in- 
terests control about 68 per cent. of the total, while 
if more liberal estimates are used the figure would be 
reduced to 57 per cent. Most of the deposits not un- 
der American control are owned or dominated by 
British capital. 


CAPACITY OUTPUT AND RESERVES OF COPPER PRODUCING COUNTRIES 1 


Producing Estimated Percentage Percentage 
Capacity 
country Output of Copper of World of Total 
Reserves 
(metric tons) Total of World 
Western Hemisphere: 
United States 928,000 57.5 34, 
Canada 58,000 3.6 3. 
Mexico 65,000 4.0 1.15 


1 Adapted from chapter by F. W. Paine in Spurr’s “Political and 
Commercial Geology.” 


HERITAGE OF COPPER 63 


CAPACITY OUTPUT AND RESERVES OF COPPER PRODUCING COUNTRIES 


(Continued) 
Producing Estimated Percentage Percentage 
Capacity 
country Output of Copper of World of Total 
Reserves 
(metric tons) Total of World 
Cuba and 
Venezuela 12,000 0.7 0.10 
Chile 110,000 6.8 37.9 2 
Peru 45,000 2.8 0.55 
Bolivia 12,000 0.8 0.10 
Total 1,230,000 76.2 76.8 


Eastern Hemisphere: 


Africa 58,000 3.6 Th 
Australia 43,000 ray 0.95 
Japan 125,000 rie § 2.2 
Spain and 

Portugal 42,000 2.6 6.2 
Russia 18,000 1.1 0.95 
Central Powers - 71,000 4.4 0.95 
Norway 19,000 1.2 0.55 
Sweden 1,000 0.1 0.04 
Other countries 6,250 0.4 0.06 

Total 383,250 23.8 Baie 

World Total 1,613,250 100 100 


Percentage of world total reserves owned by capital 
of various countries: United States, 73.6; British, 
20.8; German, 1.05; French, 0.4; Japanese, 2.2; local 
capital in producing countries, 1.95. 

“While foreign deposits may supply the world with 
copper at some future date, to-day the United States 
holds undisputed first place in copper production. 
The American copper industry was begun before the 
white man arrived on this continent, and it flourished 

2 As the large reserves of Chile are compact, distant from the market, 


and in thinly settled country, this large figure must be discounted in 
so far as it affects production. 


64 THE STORY OF COPPER 


COPPER PRODUCING AREAS OF THE UNITED STATES 


ty 


aan we 


, 


% i 
ARIZONA] WE ‘a mF 
+ \ Jegpre, O Say 
Harn gl o% F593 
muidnnsaye AR Ss ay A 
na ) oY 
e? 


EXPLANATION 
BLACK SQUARES SHOW LOCATION OF THE 
PRINCIPAL COPPER DISTRICTS, THE S/ZE 
BLING PROPORTIONAL TO PERCENTAGE OF 
TOTAL US PRODUCTION SINCE (IINING BEGAN 


NUIIBEREO CROSSES (NO/ICATE (PORTANT DISTRICTS 
OF RECENT DEVELOPVIENT THAT PRODUCED (MN 192/. 


Produc- Percentage Production in 1921! 


tion total 
No. District, State began U. 6. Percentage Rank 
1845- 
1921 
1 Butte, Mont. 1868 27 10 4 
2 Lake Superior, Mich. 1845 23 19 1 
3 Bisbee, Ariz. 1880 9 8 5 
4 Bingham, Utah 1896 7 6 6 
5 Globe-Miami, Ariz. 1881 6 16 2 
6 Morenci-Metcalf, Ariz. 1873 5 2 11 
7 Jerome, Ariz. 1883 4 6 7 
8 Ely, Nev. 1908 3 2 12 
9 Santa Rita, New Mex. 1800 2 2 14 
10 Ray, Ariz. 1911 2 2 13 
11 Shasta County, Cal. 1897 2 ie ws 
12 Ducktown, Tenn. 1850 1 3 9 
13 Foot-hill Belt, Cal. 1862 vg | age me 
14 Tintic, Utah 1880 1 wh 19 
15 Copper River, Alaska .... oF ii 3 
16 Ajo, Ariz. Rae ‘S 4 8 
17 Plumas County, Cal. eh SF 2 10 
18 Prince William Sound, 
Alaska aes hie 1 15 
19 Burro Mountain, 
New Mex. Bade oh 1 16 


20 Lake and Eagle 
Counties, Colo. Boests ie 1 ws 


HERITAGE OF COPPER 65 


on a primitive scale. It is recorded that the settlers 
discovered copper in Massachusetts as early as 1632, 
and in 1709 a company was incorporated in Connecti- 
cut for the purpose of working copper ores. The 
copper deposits of New Jersey were worked in 1719, 
and the copper-mines of Vermont date from the eight- 
eenth century. 

But the real development of the American copper 
industry began in 1844 when white men began to ex- 
ploit, as the Indians had bfore them, the richness of 
the Lake Superior native copper deposits. For years 
Michigan held sway as the great copper-producing 
State, but in 1882 Butte, Montana, produced its first 
copper and the most important copper camp in the 
world was inaugurated. A decade later the copper in- 
dustry of Arizona was established. 

For the three quarters of a century that the copper 
_ industry has existed in the United States, Arizona and 
Montana are close rivals for the honor of being the 
largest producers. Arizona, although later to achieve 
production, ranks first by a narrow margin and is 
responsible for 28.19 per cent. of the total produc- 
tion. Montana holds second place with 27.06 per cent., 
while Michigan is third with 23.18 per cent. These 
three States from 1845 to 1922 produced more than 
three quarters of the total copper mined in this 
country. Utah with 8 per cent. of the total ranks 
fourth. The fourteen important copper-producing 
States and their record during that period, as 
compiled by the United States Geological Survey, 
are: 


66 THE STORY OF COPPER 


Copper produced in the United States, 1845-1921, by States 
[Smelter output] . 


State. Pounds. Per cent. Rank. 
A laalea, Seen Gs Wechicn works Gas 675,257,584 8 
PAOLA), Otte ays a Me tenets hie tk a Nene i 8,500,925,933 28 1 
CSOULELOLIIG oo eine Wiese ort bee wee 796,185,053 6 
COROT OC: Gala atkins cts Olan Woe We clatter 290,605,186 : 10 
TANG eee Oe eee eee 114,450, 6187 (eee 11 
Michigan ye iwis ses sie sete 6,961,378,104 3 
WMEGRECATIBN Nila ate cag 8 aecete et aanerateag By 8,061,394,471 2 
IN OWL a hak Ce ei aye ete nate Se 957,508,434 5 
Weer qu MGS i cts est. secun! pe. tein sale Oi 716,203,395 7 
CONEWOI wis asin catieilnn syecel > ae aie ol ie 15,549,894 |..... 14 
Tentiesaee as eV Aha eal vaetenaele ai 398,553,000 1 9 
ESTE ie as 2 aries ee i eet ake ae 2,408,562,961 4 
Washington’). cea sweats ste ome 17,693 070 tt ae. 13 
Weyoning is) ym ne 1 hi eee oes 31,585,120 [lsc ste 12 


161,800,750. |. 41) ee 
30,107,655,570 | 100 


Other States and unapportioned 


o..0 Le ew AD eho Ses 


; (9/13 S917 SHE 1919 1920 792} ee 
ohtionsed SS SS ee (7) ra wa Arizona 

flontana 2 (2 ] (25 L2] - 
Michigen TH ee ee ae = pone 
Utah cs 7 77 ca ca [FI Utah 
griees EE Ex vo a Ae [3] Nevaca 

ew Mexico e) cz [e] ce {51 ; i 
California TZ) (7) ba ez) On i presipibee ti 
ome 12] La J cA ea —p ea {2} Afasks 
Coloredo a cs a a Bicone 

(2) [1 (9) Colorado 

Idaho ld3aho 
Washington @ 2) Wyamiin 
Missouri ZH Mashington 
Wyoming [& 4) Oregory 
Pennsylvania [ZB] 
Oregon 
Virginia 
Texas 
Vermont 


From ‘‘Mineral Resources, 1921’’ 


CHART SHOWING RANK OF STATES PRODUCING COPPER, 1845-1921 


1 Approximate production. 


HERITAGE OF COPPER 67 


While Arizona is credited with being the most im- 
portant copper-producing State, Butte, Montana, is 
by far the most important and interesting copper- 
producing camp in the world. More than one quar- 
ter of the total amount of copper mined in the United 
States has come from Butte. 

Two adventurers in search of mineral wealth, so 
the story goes, crossed the Great Divide from Virginia 
City one evening in May, 1864, and came upon a small 
pit which some forgotten miner had abandoned. From 
this six-foot pit has sprung the Original Mine of the 
Anaconda Co., now only one of the many in the Butte 
district. The barren steeply rising hill or butte on 
which the pit was located provided the name that the 
metropolis of Montana now bears. Gold, not copper, 
was the metal that Butte’s founders were seeking, and 
for three years the gravels of the regions were washed 
and made to yield yellow metal. Silver was the cause 
of Butte’s next epoch of development, and from 1865, 
when the first vein was found, to 1893, when the col- 
lapse in the price of silver occurred, silver mining was 
Butte’s most important industry. The climax of the 
production of silver ore was reached, however, in 1887 ; 
the silver and copper periods overlapped. 

Before 1880 the idea that Butte would become 
famous as a great copper producer would certainly 
have been ridiculed by mining engineers and geologists 
of the day. But the young manager of a silver mine 
believed that Butte Hill was rich in copper, and, suc- 
ceeding in making a group of California capitalists 
think so also, he acquired a large part of the hill 


68 THE STORY OF COPPER 


and set out to prove his belief. Thus an unschooled 
Irishman, Marcus Daly, established Montana’s copper 
industry. He conducted mining and smelting on a 
scale that Butte had never seen before. Night and day 
men probed the earth for the rich copper veins, a hun- 
dred furnaces raised their stacks and smoke, and lum- 
berjacks denuded whole forests to provide the timber 
to shore up excavation, cross-cut, and tunnel. Moun- 
tains of gray-green refuse and hills of black slag were 
spread over the landscape, and on the surface Butte 
became an ugly scar in virgin country. But under- 
ground, Marcus Daly was creating the first of Mon- 
tana’s great copper-mines. In 1872, earlier than 
Daly’s exploitation of the deep, rich copper, Senator 
W. A. Clark had made the first successful development 
of the copper veins of the Butte district. At this 
time the ore had to be taken overland four hundred 
miles in wagons until the railroad was reached at 
Corinne, Utah, and then it was shipped by rail to the 
Eastern smelters or even to Swansea in England. In 
1879 there was erected near Butte a reduction plant 
that cared for the ore of that district. From these be- 
ginnings, in a short forty years, Butte had given a 
metal-using world more than two billion dollars in 
mineral wealth, a large part of it in copper. It has 
produced more copper and silver than any other dis- 
trict in the world, and from it has come one sixth of 
all the copper mined in the world. 

Voleanic action brought this wealth of copper to 
Butte. The butte itself is the eroded remnant of a 
small volcano, and all the rocks of the ore-bearing area 
are igneous. The history of the copper minerals that 


HERITAGE OF COPPER 69 


are found there is one of ascending waters that car- 
ried a copper burden to the veins above. Chalcocite, 
more familiarly known as glance, is the principal cop- 
per mineral. Butte mines are nearly an exclusive 
residential section for members of the copper-sulphur 
mineral family. The other important Butte copper 
minerals are bornite, enargite, and cupriferous pyrite, 
while covellite, tetrahedrite, and chalcopyrite are less 
common. ‘he reason why the early settlers at Butte 
mined silver instead of copper was that the great 
wealth of copper was hidden underground, and it is 
only after the deposits have been penetrated two hun- 
dred to four hundred feet that the wonderful deposits 
of copper ores are found. They are at this level be- 
cause of the action of what the geologist calls ‘‘secon- 
dary enrichment.’’ The upper levels of the veins have 
been robbed by descending waters to enrich the lower 
copper deposits. Thanks to the extensive development 
work that the disputes over ownership of the ore 
bodies made necessary, the way in which the veins of 
the Butte region run has been revealed. The rocks of 
the district are traversed by a multiplicity of joints 
and fractures; in many places, by some gigantic dis- 
turbance, the rocks have slid over one another, or 
‘‘faulted,’’ to use the geological term. Because of 
this, two great mines some distance apart often send 
their shafts down into what was once a single vein. 
Arizona, the State that ranks first in copper pro- 
duction in this country, has five districts that yield a 
large amount of copper. In 1921 Arizona produced 
31 per cent. of the copper of the United States, and it 
is credited with the largest part, 28 per cent., of the 


70 THE STORY OF COPPER 


total production since 1845 despite the fact that min- 
ing there did not begin on a large scale until about ten 
years later than at Butte. 

The famous Copper Queen mine is contained in the 
Bisbee or Warren district, which ranks highest in pro- 
duction in the State in point of total production, al- 
though in recent years it has been surpassed by the 
Globe-Miami district. This mining center is very 
close to the Mexican border. Bisbee, similarly to the 
Clifton-Morenci district, the second largest total pro- 
ducer in Arizona, is the product of an invasion of lime- 
stone by granite magmas that carried copper and 
iron and deposited it in the highly heated and changed 
hmestone. In many cases percolating waters have 
concentrated the ore at lower levels by secondary 
enrichment, and this process has been responsible for 
the ‘‘cave’’ ores for which Bisbee was so long famous. 
Near the surface of the copper-invaded limestone, 
there were formed caves of irregular shape, some of 
them three hundred feet wide and seven hundred feet 
long. These were decorated on their inner surface 
with green malachite and blue azurite, set off with 
stalactites of calcite. Such artistic oxide ores are now 
virtually exhausted, and it is the more prosaic pyrite, 
or iron sulphide, that has associated with it the copper- 
containing chalcopyrite and glance, which now pro- 
duces most of the copper of the Bisbee district. Metal- 
lurgical processes are progressing so that even the 
relatively lean masses of the main porphyry are be- 
ing exploited. 

Much the same genealogical story can be told about 
the other copper-producing localities of Arizona. The 


HERITAGE OF COPPER 1 


Globe-Miami district ranks fifth in the country as well 
as second in the State in point of total production, but 
in recent years it has been the leading producer of the 
State and the second best copper district in the coun- 
try. Mining for silver began in the region in about 
1880. At Globe the deposits consist of lenticular 
masses replacing limestone in dark igneous rock. At 
Miami, only six miles from Globe, the ore minerals are 
disseminated in the shattered schist and granite. 
The copper deposits of the Morenci-Metcalf dis- 
trict were discovered in 1872, but they remained un- © 
developed for a long period because of their low grade 
and their distance from a railroad. Now in total 
production this region ranks sixth among the dis- 
tricts of the country. The ores here occur as contact 
deposits in limestones and shales intruded by por- 
phyry. The Jerome district is another important 
Arizona locality, which in total output stands seventh 
among the copper districts of the country. The ore 
occurs in schists, and consists of replacements of the 
schists by chalcopyrite, associated with pyrite and zinc- 
blende. The Ray or Mineral Creek district deposits 
are similar in geological condition to those of the Mi- 
ami district, and though it began production in 1883, 
it has become an important producer only since 1911. 
The Keweenaw peninsula in Michigan, jutting 
sharply out from the southern shore of Lake Superior, 
was for a long period the principal American pro- 
ducer and has always been an important one. The 
region is also unique as the only one in which there 
have been produced large quantities of native copper. 
Both in total production and for the single year 1920, 


72 THE STORY OF COPPER 


this district ranked third among those in the United 
States. The Indians first discovered the Lake Su- 
perior deposits and worked them on a scale astonish- 
ingly large for such primitive people. But the mod- 
ern pioneer of the great mining activity on the Ke- 
Wweenaw peninsula was Douglas Houghton, the first 
State geologist of Michigan, who was appointed in 
1837. Just two hundred and one years earlier, a book 
by Lagarde published in Paris had given an account 
of the occurrence of native copper near Lake Superior, 
and at even earlier dates Jesuit missionaries and 
early voyageurs mentioned the extensive use of copper 
by the Indians. It was a century later, in 1763, that 
a practical Englishman, Alexander Henry, visited the 
region, and a decade later he unsuccessfully attempted 
mining operations. This early history had as little 
influence on the final development of the Lake Superior 
copper-mines as did the Indian exploitation in pre- 
Columbian days. Houghton’s scientific deseription of 
the copper deposits contained in his report made in 
1841 drew attention to the region, and when the Chip- 
pewas, on March 12, 1843, ceded the land to the Gov- 
ernment, there followed a speculative craze which 
lasted for three years. The first mines opened were 
veins of the Eagle River district, which carry both na- 
tive silver and native copper and were not the layers 
of conglomerate and amygdaloid which have become 
the great producing lodes of the region. Shortly 
afterward the lodes of mass copper in the Ontonago 
district at the south end of the region were developed 
and became noted for the large boulders of metal that 
were found. In 1856 the first of the rich copper de- 


HERITAGE OF COPPER 13 


posits in the amygdaloid layers, such as the great 
Quincey mine, was opened up, and when E. J. Hulbert, 
John Hulbert, and Amos H. Scott, in September, 1864, 
uncovered a copper-bearing conglomerate, thus dis- 
covering the Calumet lode, a new epoch in Michigan 
copper was ushered in. The later history of Lake 
Superior mining is one of financial venture and con- 
solidations, combined with improvements in mining 
and metallurgical methods. While the Superior mines 
were virtually alone as copper producers in this coun- 
try until 1880-90, during the last thirty years they 
have had to sustain the rivalry of the great Western 
copper deposits. 

If you took a sharp knife and sliced off the Kewee- 
naw peninsula from one of its shores to the other you 
would see that it is made up of a large number of 
layers of rocks dipping toward the northwest at an 
angle of from thirty to eighty degrees to the horizontal 
plane. Starting from the west side of the sliced sec- 
tion and going eastward, there are layers of sand- 
stone, then layers of conglomerate. The rest of the 
sloping layers are made up of igneous rock in which 
there are interposed the copper-containing conglomer- 
ate and amygdaloid layers. All of these rocks were 
once horizontal instead of sloping, but after they were 
formed a great earth movement thrust them into their 
present position. The copper-mines follow the pay 
rock in the long sloping layers of conglomerate and 
amygdaloid rock, which is a comparatively easy mat- 
ter. 

A mountain of copper ore, the largest in the world 
in ore production, yields most of the metal produced 


74 THE STORY OF COPPER 


in Utah, which ranks fourth in total production in the 
country. This is the porphyry mass which contains 
disseminated primary chalcopyrite and pyrite, with 
secondary covellite, chalecocite, and bornite which have 
sufficiently enriched the whole mass to make it pay 
ore. ‘The mass of ore sticks up in the air sixteen hun- 
dred feet and is a mile long and half a mile wide. It is 
overlaid by a capping of worthless material, averag- 
ing 115 feet thick, which must be removed before the 
ore can be exploited. At the end of 1920 the total 
ore reserves of this deposit amounted to 364,130,800 
tons averaging 1.35 per cent. copper, not including the 
parts that have not been prospected or tested. ‘This is 
the second largest developed copper ore body known. 
When the mine was first opened the ore was extracted 
by underground workings, but it soon became appar- 
ent that it would be profitable to use steam shovels and 
the open cut method, despite the necessity of removing 
the large amount of over-burden. The mountain of ore 
is now being leveled and sent to concentrators and 
smelters at the rate of ten million tons a year, yield- 
ing about eighty thousand tons of copper. The ore 
that was mined in the early days at Bingham was not 
the disseminated material in the porphyry, but ir- 
regular replacement deposits in imestone. As late as 
1900, before the development of modern methods of 
ore treatment, the great Bingham deposits containing 
small percentages of copper were rightly considered 
of little immediate value. Of this property ‘‘The fn- 
gineering and Mining Journal’’ in an editorial headed, 
‘*A Doubtful Copper Prospect,’’ wrote as follows in 
its issue of May 29, 1899: 


HERITAGE OF COPPER 75 


It would be impossible to mine and treat ores carrying 3 per 
cent. or less of copper at a profit under the existing conditions 
in Utah. On the company’s own showing, therefore, the more 
ore it has of the kind it claims the poorer it is. 


The editor was doubtless right when he wrote; but 
in 1915 the Utah Copper Co. produced 156,207,376 
pounds of copper, from ore which yielded only 18.82 
pounds to the ton, at a net cost of 7.48 cents a pound; 
sold copper at an average price of 17.679 cents a pound; 
paid 4214 per cent. dividends on its stock; and showed 
a surplus after dividends equivalent to more than 6714 
per cent. on its capital stock. D.C. Jackling and R. C. 
Gemmel were largely responsible for proving the 
editorial wrong, and they deserve part of the credit for 
developing several of the large porphyries which con- 
tain the principal part of the American reserves. 

Utah ranks third in both possible and proved re- 
serves of the world, with Katanga first in possible re- 
serves and Chuquicamata first in proved reserves. 

Before 1903 Alaska had produced very little copper, 
but in 1922 it ranked fifth as a producer in this coun- 
try. Most of Alaska’s copper has so far come from 
the mines in the Copper River district, which operate 
on very rich chaleocite ore. This rich region was 
tapped on a considerable scale only with the com- 
pletion in 1911 of a two-hundred-mile railroad built to 
serve it, and fortunately these mines came into quan- 
tity production just in time to benefit by the war de- 
mand and war prices for copper. These deposits were 
formed by ascending thermal waters, which replaced 
limestone with copper, and the diggings of to-day do 


16 THE STORY OF COPPER 


not show the benefits of secondary enrichment. In 
the ice age, glaciers scooped off the original upper 
parts of the deposits that had been oxidized by the 
surface-waters, and at the same time these great sheets 
of ice swept away the next lower layers that had been. 
enriched. Post-glacial times have been too short to 
allow nature again to concentrate surface copper at 
lower levels, but so rich are the primary sulphide ores 
formed in limestone that man is hardly warranted in 
expecting their value to be increased by enrichment. 
Nevada, fifth in line in total copper production since 
1845, owes its place chiefly to the Ely district. In this 
region most of the producing ore bodies consist of 
great masses of porphyry which have projected them- 
selves into limestone. These are mined in part by the 
open cut method similarly to the Bingham deposits, 
and they contain only about 114 per cent. of copper. 
Ducktown, Tennessee, is the only district east of the 
Rockies, other than the Lake Superior region, that is 
important as a copper producer; and it is nearly 
as well known for its sulphuric acid as its copper. 
In smelting this ore for copper, sulphur that was harm- 
ful to vegetation was given off in the smelter fumes, 
and to prevent damage to near-by farms, the 'l’ennes- 
see courts fixed a maximum amount of sulphur that 
might be expelled into the atmosphere. This foreed 
the smelters to utilize the sulphur in the ores instead of 
wasting it, and it led to the manufacture of sulphuric 
acid, which is now used in fertilizer on a large scale. 
At one time California ranked second only to Michi- 
gan as a copper producer, but in total production it 
now ranks as the sixth State. The bulk of the Cali- 


HERITAGE OF COPPER ee 


fornia production comes from the deposits of Shasta 
County, which are of the porphyry type. Part of the 
copper is also obtained from mixed ores, in which the 
copper is subordinate to silver-lead and pyritie gold 
ores. 

New Mexico’s copper history dates from the eight- 
eenth century, when native copper was sent to Mexico 
for coinage purposes. Important modern production 
began in 1912. The Santa Rita district is the prin- 
cipal producer and in 1921 ranked sixth. The ore 
body is of the disseminated type and of considerable 
extent, but, unlike most of these ores, there is an ap- 
preciable amount of native copper present. 

Colorado and Idaho have appreciable outputs of 
copper ores, but most of the production is incidental 
to the mining of ores of other metals, principally lead 
and zine. In Georgia, Oregon, Vermont, Washington, 
and Wyoming copper deposits are also found and 
worked, but these are of minor importance. 

Our next-door neighbor to the south, Mexico, is 
credited with 4.9 per cent. of the production of the 
world in 1918 and, had conditions been more settled 
politically in the few years preceding, it probably 
would have shown a much larger production. Geo- 
logically the deposits are much like those of our 
Western States, as they are located in the same kind of 
country. The Cananea district in the State of Sonora 
is the most important copper region in Mexico and 
lies only about forty miles southwest of Bisbee, Ari- 
zona. The Boleo mines in Lower California are the 
second largest producers in Mexico. 

Canada on our north holds fifth rank in the copper 


18 THE STORY OF COPPER 


production of the world. More than half of this is 
from British Columbia, principally from the Boundary 
district, so named because it is not far from the United 
States line. Ontario is responsible for one third of the 
Canadian production and is famous for the nickel- 
copper ores of the Sudbury area. Most of its copper 
is obtained from these ores, which contain from 1 to 
2.5 per cent. of copper. As late as 1916-17 large and 
rich copper deposits were discovered in Manitoba, but 
this area is not yet opened up for large-scale exploi- 
tation, although the future promises much. Upon the 
arctic coast in the Northwest Territories, according to 
the report brought back by the Canadian Arctic Ex- 
pedition, there are deposits of native copper over an 
enormous area that resembles the important Lake 
Superior region of our own country. Evidently, even 
in these modern days, there are lands to eonquer. The 
report of the copper possibilities of the far north says: 


The copper-bearing rocks would seem to extend along the 
Arctic coast both east and west of the Coppermine river for 
about 500 miles in all, and probably many of the smaller 
islands off the coast are also of the same rocks, and the total 
area of these rocks undoubtedly amounts to many thousands 
of square miles. Comparing the early accounts of the occur- 
rence of native copper on Lake Superior with the accounts 
which we now possess of the copper on Coppermine river, and 
considering the enormous extent of the northern deposits, we 
have reasonable grounds for hope that before many years the 
Coppermine area will produce as much copper as *s now 
mined in Northern Michigan. 


Not only does Chile contain the largest mine in the 
world and the greatest known copper reserves of the 


HERITAGE OF COPPER 79 


world, but it now ranks second only to the United 
States with one twelfth of the world production to its 
credit. Chile is in its second important copper pro- 
duction period of modern times. Between 1870 and 
1882 it supplied the bulk of the copper used in the 
world, and after this time production declined con- 
siderably until 1900, when the present revival set in. 
The earliest copper mining in Chile occurred before 
the advent of the white man, and to-day at the prin- 
cipal copper-mines there may be seen the old Indian 
workings that honeycombed the hills of copper in 
search of rich streaks in the veins. The Chuquicamata 
deposits are the most extensive so far proved in any 
part of the world, and it is estimated that they con- 
tain seven hundred million tons of copper ores averag- 
ing 2.12 per cent. copper. They are comparable in 
structure to the great porphyry deposits of the United 
States such as at Bingham, Utah, and are worked in 
much the same way by the open cut method. 

The hill on which they are found is 9890 feet above 
sea-level in an arid and desolate country, and is about 
two and a half miles long and a third of a mile wide. 

This Chile Copper Co. mine and two other import- 
ant holdings, the Teniente mines of the Braden Copper 
Co. and the mines of the Andes Copper Co. that are 
not yet being worked, are all American-owned. In 
these properties are concentrated the important cop- 
per reserves of Chile; it is estimated that these mines 
could continue their present capacity output for from 
150 to 200 years. 

In Peru the second largest copper producing mines 
of South America are located. They now stand 


80 THE STORY OF COPPER 


seventh in world production. As in Chile, these are 
largely American-owned. In only a few localities are 
ores mined for copper alone, and in nine tenths of the 
output the copper has come from silver-copper or 
copper-silver ores. Bolivia, Venezuela, and Argen- 
tina are also small producers of copper. 

Japan’s copper-mines, which stand third in world 
production, are strictly Japanese in ownership and 
management, as the state owns all ores and grants the 
right to work them to individuals or companies of 
Japanese nationality only. Until a few years ago, 
Japan’s production exceeded that of Chile, but recently 
copper has been imported on a rather large scale. 
Geologists believe, however, that in the future Japan 
will be able to supply its own needs. Copper is the 
chief metallic product of Japan, and it occurs in vir- 
tually every province of the island. It has been mined 
from time immemorial. The principal mines include 
the Ashio, Kosaka, Besshi, and Hitachi, each of which 
has produced more than ten thousand tons of copper in 
a year. 

Rio Tinto has been a synonym for copper ever since 
the Phenicians worked this great Spanish copper- 
mine as early as 1240 s.c. In reserves and in the 
amount of ore that has already been extracted, the 
Spanish copper deposits are remarkable. The ore al- 
ready mined is estimated at more than 125,000,000 
tons, the proved reserves are more than 230,000,000 
tons, and in 1920 there were 25,000,000 tons in the 
stock piles undergoing the lengthy leaching process . 
which is used in extracting the copper. Like those at 
Bingham, the deposits at Rio Tinto are worked mainly 


‘yey ‘weysurg je suru s Auedutog Jaddod yeiQ ey} Jo Mara ouedire uy 
adaddOO AO NIVINONOW vV 


‘ISOM SurIyoo, ‘sourur 9}3ng 924} JO MoIA VW 


VNVINOW ‘ALLO AO «.dWVO, UWHddOD LVAAD AHL 


HERITAGE OF COPPER 81 


by open cuts, and this method has been followed from 
the earliest days, though because of the depth of some 
of the workings a system of stoping sometimes is used. 
To-day railroads run on the tops of waste piles of 
over-burden that were placed there by manual labor 
in the days of the Romans. Rio Tinto has always been 
controversial ground for geologists. Some believe the 
deposits to have been formed by the intrusion of 
molten sulphides, segregated from an igneous magma, 
but others assert that they are replacement deposits. 

Virtually all the other European countries produce 
some copper. The Mansfeld shales in Germany yield 
a fair quantity of the metal, but Germany is dependent 
on outside sources for the large bulk of its copper. 
Under the old régime Russia supplied some of its in- 
ternal demand for copper from its own mines. Nor- 
way and Sweden contain important copper-mines, 
which are usually low in copper values. England 
still obtains a small amount of copper from the Cornish 
tin-mines that in the bronze age conveniently fur- 
nished both the tin and copper for the early Britons. 
France and Italy produce considerable quantities of 
copper-containing pyrites. Finland has recently de- 
veloped mines that promise to be as important as those 
of Norway and Sweden. They are also of the same 
type. In Siberia, eastern Russia, and the Russian 
Caucasus there are deposits, not now worked, that 
promise production sufficient to place that country 
among the important copper countries. 

The island continent of Australia in the past has 
been relatively more important as a copper producer 
than it is now. The best-known Australasian mine, 


82 THE STORY OF COPPER 


perhaps, is the Mount Lytell in Tasmania. It is an 
old and steady producer and is one of the lowest grade 
profitable mines in the world. 

Africa is becoming of increasing importance as a 
copper producer because of the deposits of the Ka- 
tanga region of Belgian Kongo. These are very rich © 
in copper, some of them running as high as 30 per 
cent., and the developed reserves alone assure a hun- 
dred years’ supply of 8 per cent. ore. Other im- 
portant African deposits are located in the Union of 
South Africa and Southern Rhodesia, whose mines are 
geologically a part of the Katanga district. 

China is a somewhat unknown quantity as to copper 
resources because of the backwardness of its people, 
who, unlike the Japanese, work the mines in the same 
way that their grandfathers did before them. China’s 
chief mine, the Tung-chuan-fu, has a yearly output of 
about a thousand tons of copper, and this district has 
been worked for hundreds of years; but those mines 
that have been investigated promise little copper if 
worked by modern methods on a considerable scale. 

When the great copper-mines of the world are being 
described, we must not forget one of them that in area 
and closeness to all of us is the most important in the 
world. The city in which you live is a vast copper- 
mine, but the ore is too valuable in most cases to dis- 
turb for its low copper content. There is a gradual 
slow process of concentration in progress during the 
daily life of the city. Copper, brass, and bronze arti- 
cles become obsolete or damaged and finally find their 
way to the bins of concentrate. You will find these 
storehouses of city-mined copper in some side street 


HERITAGE OF COPPER 83 


in the factory district, with the signs of ‘‘Junk’’ and 
‘*Qld copper and brass bought for cash; best prices.”’ 
In the statistics of copper production, salvaged copper 
is referred to as ‘‘secondary copper,”’ and it is an im- 
portant factor in the copper market. Each year be- 
tween 600,000,000 and 700,000,000 pounds of such re- 
fined copper from secondary sources are produced in 
the United States. 

The copper-mines that civilization is creating have 
been drawn upon in times of dire need. When Ger- 
many was cut off from customary imports of copper 
during the war, roofs, church bells, kitchen pans, door- 
knobs, and all sorts of copper-containing articles went 
into the melting-pot to supply the German armies with 
red metal. 

The war caused another interesting case of the ex- 
ploitation of secondary copper. Chinese copper coins 
contain 85 per cent. copper. In 1916 copper rose in 
price to such an extent that Japan found it profitable 
to import large quantities of these coins and extract 
the copper. One concern alone in 1917, regardless of 
the effect on Chinese finances, contracted for two hun- 
dred thousand tons of these Chinese coins. The sixty 
thousand tons of refined copper a year from this 
secondary source allowed Japan to make heavy ex- 
ports of copper during the war. 


CHAPTER IV 
WINNING METAL FROM THE EARTH 


In man’s struggle to free copper from the other 
elements or rocks and minerals with which it is com- 
bined or mixed, he supplements and improves upon 
the methods that nature herself has used in geologic 
times to create the specially rich deposits of copper- 
bearing material that man calls mines. From the 
time, eons ago, when perhaps other elements in the 
heat of stars combined to form copper, until the final 
electrolytic refining of to-day, which purifies copper 
to do the world’s work, concentration of the copper has 
been the goal. During the ages that the earth’s crust 
was taking its present form, nature was not always 
successful in her concentrating processes; in fact, one 
would suspect that at times she lost interest in stor- 
ing up minerals rich in copper and had a fling of ex- 
travagance. But we have seen how rising hot water 
scattered copper minerals in rocks near the surface 
and later how the waters of rains gathered this cop- 
per together to form a concentrated benanza layer as 
a prize package for lucky and foreseeing miners, and 
we have seen how large volumes of rocks were impreg- 
nated with copper or copper minerals. After nature 
performed her process of concentration and after man 


has discovered where she has laid up her treasure, 
84 


WINNING METAL FROM EARTH 85 


then the human mind must evolve the best methods of 
obtaining red metal from unpromising earth. 

Man’s first step in his concentration of copper is 
mining, and the way in which he goes about it depends 
upon the condition in which geological processes have 
left the ore. If the deposits consist of rich veins, as 
they do at Butte, he must sink deep shafts and run 
lengthy tunnels or drifts through which the ore may be 
carried to the surface. On the other hand, if a 
mountain of copper has been created,—a copper moun- 
tain that contains only 2 per cent. metal at the most, 
—such as at Bingham, Utah, then it is cheaper and 
easier to call upon steam-shovels and railroads to 
transport the whole hill to the concentrating-plant. 
By these two methods, underground and open-cut min- 
ing, the mining of the world is done. 

If you saw a car-load of copper ore, unless you were 
well acquainted with copper mining, you would prob- 
ably think that it was only so much rock. You would 
be about 98.37 per cent. right, for the average recov- 
erable content of copper in copper ore produced in 
this country in 1920 was only 1.63 per cent. From 
every ton of copper ore an average of only 32.6 pounds 
of copper was obtained. This seems a very small 
amount,—the value of the metal to the ton, including 
forty-six cents’ worth of gold and silver, is only $5.02 
when copper is fourteen cents a pound,—and it would 
be except for the fact that large quantities of ore are 
mined and treated every year. The value of copper 
production in 1920 was $222,457,000, while in the peak 
year of 1917 it was $514,911,000. It is the fourth larg- 
est mining industry in the country, only coal, petro- 


86 THE STORY OF COPPER 


leum, and iron surpassing it. More than forty thou- 
sand men were employed in 226 copper mines of the 
country even during the poor year of 1919, and this is 
nearly as many men as were then required in the iron 
mines. 

When a copper deposit is suspected the first step 
toward mining is to prove that the ore is there. Sink- 
ing a large shaft that would allow a close-up inspec- 
tion of the underground strata used to be the only way 
by which riches of the earth could be discovered, but 
modern methods send a drill down in the small round 
opening that it makes to bring back the desired in- 
formation about the deposits. Unless valuable min- 
eral is exposed at the surface and there is a good 
chance of the shaft paying its own way down from 
the surface of the earth, the drill method is usually 
used to-day. Often the familiar ‘‘churn’’ drill, similar 
to the ones you have no doubt seen drilling wells or 
foundation test-holes, is used, but more frequently on 
important developments black diamonds cut the way. 
A hollow steel rod, in whose lower cutting periphery 
small black diamonds are set, will cut through rock, 
and from the cylindrical core that rises in the pipe 
the kind of deposit can be determined. LEven after the 
shafts are dug and the underground workings are in- 
full sway or after the steam-shovels have begun their 
devourings, drilling is used to guide further exploita- 
tion of the mine. 

Say ‘‘mine,’’ and the ordinary person who uses the 
products of mines daily but has never seen one will 
usually think of a hole in the ground. His idea is 
correct, to be sure, but he probably does not realize the | 


WINNING METAL FROM EARTH 87 


elaborate scale on which mines are built. If a modern 
sky-scraper, even the largest of them, were buried in 
the ground it would be small compared with some of 
the mines from which copper ore is obtained. The 
Woolworth Building is eight hundred feet high, while 
shafts more than a mile, 5280 feet, deep lead to copper 
diggings. Hundreds of miles of underground passage- 
ways are dug. Great and extensive elevating systems 
are installed and miles of subterranean electric rail- 
ways are built. Running water requires large pump- 
ing plants to remove it, and fresh air is forced into the 
depths by large fans. The mine is a community in 
itself. And, like a huge office building, it is not a 
dwelling-place for man, though it may be for mules 
and horses, who often live for years below ground. 
Unlike a sky-seraper, the mine is built from the ground 
down and not from the ground up. The chief idea is 
not to place material into the mine structure but to 
take it out. And the finish of the interior is that 
which is fashioned by the tools of the men who spend 
their working days there. 

When the miner goes to work in the morning, he 
reports at the top of the mine’s ‘‘elevator’’ shaft. 
There he enters the cage, as the steel platform at- 
tached to a heavy wire cable is called. A hoist driven 
by a steam or compressed air engine or electric motor 
lowers the cage down a timbered and fire-proofed shaft 
to his ‘‘floor,’’ which may be from 3000 to 4000 feet 
below. When the miner arrives at the proper point in 
his downward journey he scrambles out into a station, 
which, like all the rest of the underground workings, 
is a cavern hollowed out by man. From this room he 


88 THE STORY OF COPPER 


enters a ‘‘level’’ or tunnel. This is one of the main 
corridors of the mine, and on the way down many 
similar to it have been passed. Traveling along the 
level he meets steel ore-cars hauled by a small electric 
locomotive that derives its power from current car- 
ried by a copper trolley-wire. Near by this raiload 
there flows a miniature river hurried on its way by 
gravity. Even the atmosphere the miner breathes 
may be controlled by machinery, and he feels the gentle 
rush of air created by distant ventilating-fans. For- 
ests have been sacrificed to provide the great sawed 
timbers that support the workings and prevent them 
from cavingi 

He turns a corner into a cross street running at 
right angles to the level. If you asked him where he 
was he would say, ‘‘In a cross cut.’’ This tunnel takes 
him closer to the chamber which will be enlarged 
through his mining of copper ore. Finally this cham- 
ber, or the ‘‘stope,’’ is reached, and the day’s work 
begins. 

When the excavation of a stope is begun a tunnel 
ealled a drift is driven into the area that is to be robbed 
of its ore. Explosives do the heavy work after they 
have been placed in a position so that they can. The 
first step toward removing rock in any part of the 
mine is usually the drilling of holes preliminary to 
blasting. Air-drills are used almost exclusively to 
penetrate the rock as deep as seven to ten feet. After 
the explosive, usually dynamite, is placed snugly in 
these holes, it is fired by means of a fuse and copper 
primer, or an electric blasting machine that operates 
through a copper wire. This shatters and breaks the 


- WINNING METAL FROM EARTH 89 


ore to the floor of the stope, and it is then ready for 
loading into ore-cars either directly or after sorting 
to remove waste pieces. The size of the excavation 
and the methods by which it is hewn out of the rock 
are dependent upon the character of the rock, the size 
of the ore veins or bodies, and a number of other 
factors. Whether the miners start at the top of the 
volume of ore and dig their way downward or whether 
they tackle the ore from below and undermine it also 
depends upon how well the rock walls will support the 
stress and the plan of the mining operations. 

In some cases it is not practicable to run the neces- 
sary trackage for the ore-cars all the way up to the 
stope, and then the ore is shoveled or chuted to the 
nearest level equipped with transportation facilities. 
Often inclined shafts, called ‘‘winzes,’’ between floors 
or levels of the mine are cut in order to allow the ore 
to flow by gravity from the stope on one level into ore- 
cars on the level below. The engineers have found 
that it is cheaper to let the ore carry itself to installed 
trackage and go to the trouble of raising it an extra 
hundred feet or so than to construct a special branch 
of the mine railway to haul out the ore. 

The cars carry the ore to the shaft, where they are 
either dumped into large bins or receiving-pockets or 
the cars themselves are rolled upon platfoms, called 
cages, and hoisted to the surface. When receiving 
pockets are used to store the ore at the junction of the 
levels and the shaft,—and this is the usual method,— 
skips, large containers holding as much as ten tons 
of ore, are used to carry the ore to the surface, where 
it is dumped and stored in the main ore bins until it 


90 THE STORY OF COPPER 


can be transported to the concentrating-plant or 
smelter. 

When the earth is robbed of its copper treasure, a 
void is created that must be reckoned with. The rock 
above is quite willing to drop down into the vacant 
space unless the miner provides a substitute support 
for it. At one time timber performed this function, 
but as the forests diminished and wood became a 
costly replacement of rock other methods have been 
used. Often the filling-material of worked-out stopes 
is waste rock that has been mined in getting to the 
ore. Paradoxical as it may seem, rock fills much 
more space after the miner has broken it up than it 
does in its natural state. This is because of the air 
spaces in broken material. The mined ore itself is 
often used temporarily for supporting excavations, 
and it may serve in this capacity for months before 
it is sent to the surface to be smelted. In other meth- 
ods pillars of ore are left standing to carry the weight 
of the superincumbent rocks, or artificial pillars are 
built of timbers and waste rock. 

If the mine excavations are narrow the timber sup- 
port may consist simply of single timbers called 
‘‘stulls’’ bridging from wall to wall. For wider open- 
ings ‘‘square-set’’ timbers consisting of a frame- 
work of heavy wood are used. Cribs, built of criss- 
crossing hollow squares of timbers, are also employed 
in holding up hollowed-out rock. 

In cone system of mining, the supports are purposely 
made so weak that at the proper time the worked-out 
portion of the mine will cave in. After the upper part 
of the mine has been exploited by ordinary under- 


WINNING METAL FROM EARTH 91 


ground methods, the whole honeycombed block of 
ground is weakened and allowed to crush down. Then 
a main level is driven a hundred feet or so below the 
bottom of the floating mass of old mine timbers and 
waste, and mining by the caving system begins. 
Winzes are cut upward and the area just under the 
caved-in material is stoped out. When all the ore 
possible has been taken out, this part of the mine is » 
allowed to cave in. This is continued downward un- 
til finally the main level is reached and the process 
starts again. Sometimes a variation of this method of 
mining is used and the ore excavation begins at the 
bottom of the hundred-foot layer of solid rock instead 
of at the top. When this is the case the remainder of 
the solid rock is allowed to cave in along with the float- 
ing material on top, and excavation is continued in 
the half-broken rock. Caving methods are used in 
some of the Arizona and Nevada copper fields. 

It is hard to realize the vast extent of the diggings 
in an underground mine no matter how impressive a 
photograph of the surface buildings may be. The 
total length of the underground passageways of the 
Anaconda mines at Butte alone stretch seven hundred 
miles, and thirty-five miles are being added each year. 
The volume of excavations from which the ore is ac- 
tually extracted is ten times that of the passageways. 
In mechanical and engineering equipment as well as in 
mere extent the important underground copper mines 
would awe us if we could go and see them. 

A quarter- or half-mile below the surface fully 
equipped engine-rooms may be found. Some of these 
contain the pumping engines that continually rid the 


g2 THE STORY OF COPPER 


lower levels of the mine of the ever-encroaching water. 
Kilsewhere large ventilating-fans will be found, and 
electric power substations that regulate the current 
for the electric locomotives are also buried in modern 
man-made caves. The power cables have special en- 
trances to the depths of the mines through holes made 
by the diamond drill. Extensive communication sys- 
' tems of telephones, buzzers, and bells are installed as 
a part of the operating and safety systems. In some 
cases the large hoisting-engines whisk the heavy ore- 
skips at the speed of nearly a mile a minute. For 
safety the brakes of these powerful pieces of mechan- 
ism must be strong, and their control must be as exact 
as that of passenger-elevators in large office buildings 
in cities. 

Underground transportation in mines has undergone 
a revolution in the last few years. Just as the auto- 
mobile has relieved the horse of the burden of street 
traffic so the electric locomotive has displaced the mine 
mule. In former days the mules and horses that 
hauled the ore-cars over the rails often lived their 
lives in the depths of the mines. Locomotives pro- 
pelled by compressed air began to supersede the ani- 
mals, but this type has given way to either the trolley 
or storage-battery electric locomotive. 

Besides the continual struggle with the ore-bearing 
rocks that is the reason for the existence of the mine, 
the operators of underground mines must fight fire, 
water, and bad air. When timber is carried into the 
mine to supply the supporting power of the ore that is 
removed, it brings with it the possibility of fire. This 
fact is, indeed, one of the reasons why the use of tim- 


WINNING METAL FROM EARTH 93 


ber is on the decline. Extensive fire-fighting and fire- 
protective systems have been installed in many mines. 
Defective electrical equipment and incendiarism or 
carelessness are the most common causes of fires, but 
fires from these causes are generally discovered and 
extinguished before they become serious. On the 
other hand, spontaneous combustion is responsible for 
most of the large fires. Movements of the ground, 
high temperatures of the rocks themselves, and decom- 
position readily set fire to inflammable substances such 
as tarred rope, canvas, dry timber, manure, and hay. 
Even the heat resulting from oxidation of fine broken 
sulphide ore is sometimes sufficient to set fire to tim- 
bers. Large and troublesome fires are often com- 
batted by depriving them of the air that is necessary 
for their existence, and if they are caught young 
enough this smothering method is often successful. 
In some cases, however, the mine fires are older than 
many of the miners themselves; for instance, the St. 
Lawrence mine at Butte has been on fire since 1889. 
Regions on fire are reached by water sent down 
through diamond drill holes in many cases, and one of 
the latest methods used is to accompany the water with 
fine waste mill tailings that gradually fill up the ex- 
cavations inhabited by the fire. A layer of artificial 
stone is used to fireproof the shafts and main levels of 
many of the large mines, particularly in the Butte 
camp. The timbers that line the passageways are 
covered with light chicken-wire, and a coating of Port- 
land cement mortar is shot on with a gun-like machine 
that mixes the mortar at the same time that it ap- 
plies it. 


94 ‘THE STORY OF COPPER 


Water is troublesome in a mine in two forms, in the 
liquid state as we ordinarily see it and in the air. Or- 
dinary water is handled by extensive pumping systems 
or special skips that remove the water from sumps into 
which it is allowed to run at the bottom of the shafts. 
When the lie of the ground permits it, special drain- 
age tunnels, called ‘‘adits,’’ may be run out horizon- 
tally to the surface. When the water is in the air it is 
handled by the ventilating-systems that keep the air 
of the mine pure and fit for the miners. 

A constant change of air is needed in the most re- 
mote corner of a copper mine, not only because a con- 
tinuous supply of oxygen is needed for men, animals, 
and lights, but also to remove the gases from fires 
and blasting operations, and to reduce high heat and 
humidity. Although copper mines are free from the 
noxious and explosive gases that cause so much dan- 
ger and damage in coal mines, still, because copper 
mines are often deeper, the amount of heat that must 
be removed by ventilation is in many cases greater. 
Men and animals in working give off an amount of 
heat that must be reckoned with, but a far larger 
amount is emitted by the decaying of the mine tim- 
bers and the electrical apparatus. Relatively large 
amounts of heat are thrown off into the mine by the 
electrical equipment; it is estimated that such equip- 
ment consuming approximately 7350 kilowatts will in- 
crease the temperature of five hundred thousand cubic 
feet of dry air 13.7 degrees Fahrenheit each minute. 
As the depth of a mine increases the rocks become hot- 
ter, and the ordinary increase amounts to about one 
degree for every hundred feet of depth. Rock tem- 


WINNING METAL FROM EARTH 95 


peratures as high as 158 degrees Fahrenheit with air 
at 135 degrees have been encountered in some deep 
mines, and even under these conditions mining has 
been carried on, though not for long periods. These 
excessive temperatures are the exception, but in some 
of the deeper copper mines temperatures up to 110 are 
frequently recorded. The elaborate ventilating-sys- 
tems must not only reduce the high heat but also re- 
move the air containing large amounts of water vapor. 
High humidity is just as objectionable a condition as 
high temperature from the point of view of the mine 
worker. In the Anaconda mine at Butte, fans in 
twenty-nine air-shafts handle more than two million 
feet of aira minute. As there are approximately five 
thousand men at work at one time in the mine, each 
man is allotted four hundred cubic feet of air each 
minute. Proposed installations will increase this 
amount to six hundred cubic feet. Elaborate devices 
are employed to speed the air through the shafts and 
levels with the least possible resistance. In addition 
to fireproofing the timbers with cement mortar, slabs 
of smooth-surfaced concrete are fitted in between the 
projecting posts, and the levels and shafts are thus 
made as slippery to the air as the modern concrete 
pavement. The paths that the air must travel are 
carefully mapped, and air-tight doors are erected to 
keep it out of the passageways where it should not go. 
All equipment in the underground tunnels is designed 
so as to offer the least possible obstruction to the air. 
In some cases the large ventilating-fans cannot force 
the air into stopes that are being worked, and where 
such dead ends occur smaller portable fans boost and 


96 THE STORY OF COPPER 


relay the air through canvas or metal pipes leading 
to the face of the workings. 

The deepest copper mine in the world is one located 
in the Lake Superior, Michigan, district. It is No. 5 
shaft of the Tamarack mine, which has reached a verti- - 
cal depth of 5308 feet, just a little more than a mile. 
In the mines at Butte depths of 3400 to 3700 feet 
have been reached, while the equipment installed in 
certain mines will allow a deepening of the mine to 
five thousand feet without further change. How much 
deeper mines of the future will be is a question. There 
is little indication that the ore in most of the present 
deep mines will be exhausted at still lower levels. 
When depths of 7000 to 8000 feet are attained the safe 
working limit of a rope supporting only its own weight 
would be reached, but this hindrance to extremely deep 
mines can be overcome by hoisting in stages. Hven 
now one-stage hoists of more than 3000 feet are un- 
common. Other difficulties come with depth, how- 
ever. These include high temperature and excessive 
pressure on the rocks, which sometimes causes them to 
explode or flow. 

We have seen how nature in some 5 Gates has been 
kind enough to create veritable mountains of copper- 
containing rock. It is true that these large masses 
contain even smaller amounts of the red metal than 
the ores which must be brought from greater depths. 
But leanness has been compensated for by closeness 
to the surface, and large amounts of low-grade ore 
are mined to-day by steam-shovels and full-sized steam- 
locomotives and railway-cars in the open sunshine in- 


stead of by pick and shovel and dinky railroad equip- 


Courtesy American Institute of Mining and Metallurgical Engineers 


AN ELECTRIC “MULE” 


Deep underground in a Butte mine. This storage battery locomotive runs 
on a track 18 inches wide. 


Courtesy American Institute of Mining and Metallurgical Engineers 


LOOKING DOWN THE SHAFT OF ONE OF THE BUTTE MINES 


_All of the timbering has been given a coat of cement mortar as a protection 
against fire and decay. 


*19dd0d S1[][e}JOW OFUL Pd}IZAUOD SI 9}}eUI Ud}OUI dy} J10F7 


VWNVINOW ‘VGNOOVNV LV SYYOM NOILONGHA VGNOOVNV AHL LV SYALYHANOD ASNAWWI AHL 


WINNING METAL FROM EARTH OF 


ment in underground darkness. When some of these 
large deposits now worked by open cut methods were 
first opened, underground mining was practiced. It 
soon became apparent that even though a large amount 
of worthless overburden would have to be removed it 
would be more economical to mine from the surface on 
a large scale. Notable examples of open cut copper 
mining are the immense deposits at Bingham, Utah, 
from which the largest tonnage of ore in the world is 
obtained, the Rio Tinto mines of Spain, and the Chu- 
quicamata deposits in Chile. Open cut methods are 
also used in some fields in Nevada, Arizona and New 
Mexico. By mining with a steam-shovel at the surface 
slow and tedious excavating is avoided, little or no 
timber is required, pumping, ventilating, and hoisting 
troubles are virtually unknown, and the miners are 
able to work under as pleasant conditions as are ex- 
perienced by the crew excavating the foundations for a 
sky-scraper. : 

It is peculiarly fitting that copper as a metal does 
its share in releasing more copper from the ground. 
After the blasting-holes are drilled a copper cap sets 


- off the explosive that breaks the ore. Copper wires 


carry the current to electrically driven pumps lined 
with bronze to prevent corrosion by the acid mine 
waters, and wherever electricity for power or signal is 
used in the mine there copper must be. - 

At the surface of the extensive underground mines 
or near-by the hills of copper that are being leveled, 
the companies operating the mines have built small 
cities in which the concentrating, smelting, and in some 
cases refining and manufacturing of the copper are 


98 THE STORY OF COPPER 


carried on. With the exception of the Lake Superior 
region all of the large copper camps are located at 
long distances from the densely populated parts of the 
country and are isolated from other large communities. 
For this reason the companies have also had to build 
and maintain in many cases the residential sections of 
the communities dependent upon the copper industry. 
Although the miner may refer to the vicinity of the 
diggings in which he works as a camp, he uses this 
term in memory of the pioneers who established the 
industry. The copper camps of to-day are modern 
cities comparable in many respects with communities 
which have happier natural surroundings and closer 
contacts with the large centers of culture. 

What would Agricola, author of one of the ealiest 
mining treatises, published in 1550, say if he could see 
a modern copper mine? How astonished an Indian of 
pre-Columbian days would be if he could be brought 
to the present-day scenes of his primitive copper min- 
ing. How impressed and awed he would be if a large 
engine should drop him a mile and a half on the angle 
at the rate of several thousand feet a minute, into the 
depths of a large Keweenaw copper mine. Despite 
our tendency to smile when we look at Agricola’s wood- 
cut showing a miner descending into a mine through 
the simple expedient of ‘‘sitting on the dirt,’’ we should 
remember that even in those times the fundamentals of 
mining were not new and that it was six thousand or 
more years ago that unnamed Egyptian engineers or 
their predecessors initiated some of the methods that 
are systematically applied on a modern extensive scale 
to-day. | 


WINNING METAL FROM EARTH 


= 


a, Ay 
aes ZF 


From a woodcut in Agricola’s ‘‘De Re Metallica,’’ published 1550 


SIXTEENTH-CENTURY METHODS OF DESCENDING 
INTO A MINE 
A. Descending into the shaft by ladders. 


B. By sit- 
ting on a stick. OC. By sitting on the dirt. D. Descend- 
ing by steps cut in the rock. 


OY 


CHAPTER V 
FROM HEARTH TO INGOTS 


As soon as a modern chunk of copper ore has gone 
through the racking trials of being mined and brought 
to daylight, it finds itself running the gauntlet of 
water, fire, and electricity because of man’s effort to 
separate the copper from the gangue with which it has 
been associated in the lower regions. It finds extensive 
plants and machinery concentrated upon the work of 
reducing to copper thousands of tons of ore in the 
least possible time at the least possible expense. 

After the piece of ore has been disturbed by a blast 
in the underground stope thousands of feet below, it 
may seem to have been selected because of its richness, 
for transportation to the upper regions. But when it 
rattles down into a great ore-bin along with tons of 
similar chunks, it turns out not to be so exclusive. As 
the concentrating process goes on, and the ore is 
crushed, jigged, slimed, roasted, converted, fused, and 
thoroughly intermingled with other copper, its last 
suggestion of individuality must vanish. 

While the first step in man’s isolation of copper 
from its ores is taken in the underground excavations 
in the mine when the rocks containing ore are sep- 
arated from those that do not, it is not until after 
the ore is brought to the surface that the systematic . 


process of elimination of waste matter begins. 
100 


FROM EARTH TO INGOTS 101 


Physical methods of separating members of the cop- 
per mineral family from the associated rocks are 
used in initial steps. Water acts as the medium in 
which these separations are performed. After a large 
amount of barren material containing no copper has 
been culled out, fire is called upon to disunite the cop- 
per and whatever elements it may have been associ- 
ated with. This is rather a complicated process, and 
in the end copper reaches a high degree of refinement. 
The copper that is to enter the electrical field must be 
purer than that which is to be used for rougher work, 
and for this reason much copper undergoes electro- 
deposition to cleanse it of all but the most minute 
amount of contamination. Man has found that such 
extreme purity is desirable for copper that is to be put 
to all sorts of uses, and he now requires or prefers it 
in the case of much copper not used electrically. 

If you are interested in Just how this is done, let us 
follow the various courses that a piece of copper 
may take in traveling from earth to ingot through the 
large Anaconda reduction and refining works in the 
Butte district. We shall take side-trips to other plants 
and compare their methods, with an occasional glimpse 
of the past. 

As the ore comes from the mines and enters the 
storage-bins it usually ranges from about a foot and a 
half in diameter to fine dust. Before it can be put 
through the mechanical processes that will separate 
the rich from the poor or barren ore it passes through 
large crushers similar to those that may be seen at any 
‘ rock-quarry. These smash the large pieces into 
smaller ones. Before and after passing through this 


THE STORY OF COPPER 


102 


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FROM EARTH TO INGOTS 103 


reducing process, the stream of ore passes over screens 
that segregate all pieces between certain sizes and col- 
lect them for a journey on the road to refined copper. 
_ A two-inch piece is the largest that is allowed to start 
' through the concentration process; the smallest is the 
finest dust. 

The success of the first part of the concentration 
process depends upon the fact that the minerals con- 
taining copper weigh more for a given volume than 
those that do not. You have read how in the early 
days gold miners panned the gravels of the river bed 
and won their wealth by this simple means. Gold- 
bearing gravels placed in a tin basin somewhat like 
that in common use to-day were swished about in a 
peculiar way in water so that the heavier gold settled 
at the bottom and the lighter quartz flowed over the 
brim. The extensive jigs and concentrating-tables at 
the Anaconda works use exactly the same principle in 
separating the copper ore and gangue, despite the fact 
that the peculiar knack of panning is standardized. 
Because the difference in specific gravity of the copper 
minerals and their gangue is much less than the dif- 
ference between gold and the quartz gravels, copper 
concentration must be more finely adjusted; as the re- 
ward for concentrating a given amount of copper ore 
is far less than was achieved by lucky forty-niners in 
working over the same amount of gravel, copper con- 
centrating must be done on a vaster scale. 

The Hartz jig is the machine that accomplishes the 
first separation of heavy copper-rich material from the 
light and more barren rock. Into a formidable bat- 
tery of these jigs, the crushed ore, ranging in size 


104 THE STORY OF COPPER 


between two inches and three-eighths of an inch, is 
fed with water. In each jig a plunger produces rapid 
upward pulsations of water through the bed of mineral 
and allows the heavy valuable pieces to settle to the bot- 
tom, while the less rich ore stays on top. The layer of 
lower ore, or concentrate, passes out of the lower end 
of the jig through a slot discharge, while the lighter 
material flows over the end. The particles of ore that 
are selected in this way escape the rest of the con- 
centrating process and immediately enter the stage of 
fire. This concentrate is rich enough to be sent di- 
rectly to the blast-furnace for smelting, but the re- 
jected material, called ‘‘middling,’’ passes through 
rollers that crush it still finer and enters the Evans jig, 
a machine similar to the Hartz jig, adapted to handle 
ore from three-eighths to one-sixteenth of an inch in 
size. In this machine a separation between rich and 
lean ore is again made by very similar processes, and 
in this case the concentrate is sent to the bins that feed 
the roasting furnace. The middlings pass through an- 
other crushing experience in a battery of rollers that 
make them still finer and prepare them for the Wil- 
fley tables. To the output of these rollers there is 
added the part of the original ore that was finer than 
one-sixteenth of aninch. Included in this combination 
there is a large amount of extremely fine dust that 
makes ‘‘slime’’ when it is added to water. Ore slime 
is not green like the slime of ditches; it is nothing 
more than very finely divided ore, too fine to be af- 
fected by the concentrating-tables. To separate it 
from the coarser material a cone-like apparatus is 
used, and the slime that issues from the top is sent 


FROM HEARTH TO INGOTS 105 


directly to the flotation process. From the bottom of 
the de-sliming cone the coarser material goes to the 
Wilfley tables, which do this work because of the 
difference in specific gravity of the ores, but use a 
different sort of dance from that practised by the 
Hartz jigs. The Wilfley tables move a thin bed of ore 
forward as the result of a peculiar jerk imparted by 
the driving-mechanism, but the concentrate moves with 
greater momentum than the middling because of its 
greater weight to a given volume. The shaking action 
slightly loosens the bed of ore so that the concentrate 
settles below the middling. The wash water, flowing 
across the table at right angles to the direction of the 
jerking motion, carries the middling over the lower 
edge of the table while riffles guide the concentrate to 
the end of the table. The rich concentrate from the 
tables is added to the supply for the roasting-furnaces. 

The ore rejected by the tables is sent to large re- 
volving Hardinge mills in which many balls pound it 
into a powder about as fine as cement. The finely di- 
vided ore is now ready to enter upon its final step in 
the wet concentrating process, that of flotation. 

Since early times advantage has been taken of dif- 
ference in specific gravity in crude concentrating 
processes. The miners of Agricola’s time crushed 
their cre in stamp-mills and then built primitive con- 
centrators consisting of riffles that caught and held 
the heavier particles of the ore as it was washed down 
a sluice. A very similar apparatus is used in gold 
mining to-day. But in precise application, efficient 
system, and vast scale, the concentrating methods and 
plant of to-day are a true modern development and are 


106 THE STORY OF COPPER 


S SS = wks gy) ore yy i vd 


SA aR! 


1 
at 


re 


Ce SECON 
2 Sf N ee 


From Agricola’s ‘‘De Re Metallica,’’ 1550 
ROASTING COPPER MATTE 


A, B. Two furnaces. C. Tap-holes of furnaces. D. Forehearths. E. Their 
tap-holes. F. Dipping-pots. G. At the one furnace stands the smelter carrying 
a wicker basket full of charcoal. At the other furnace stands a smelter who with 
the third hooked bar breaks away the material which has frozen the tap-hole of 
the furnace. H. Hooked bar. I. Heap of charcoal. K. Barrow on which is 
a box made of wicker work in which the coals are measured. lL. Iron spade 


FROM EARTH TO INGOTS 107 


as far removed from the sixteenth century concentrat- 
ing process as the ‘sitting on the earth’’ method of 
descent is from the large mine-shaft hoisting-engines 
of to-day. 

But the concentrating process that has made possible 
the development of low-grade copper deposits on a 
large scale depends upon the fact that fine particles of 
heavy copper ore can be made to float while the lighter 
pieces sink. A woman invented this seemingly para- 
doxical process of flotation. Several stories have 
been told about the discovery of the basic principles 
of the process. One is that the wife of a miner dis- 
covered while washing overalls that copper grains in 
the dust and dirt on the garment rose to the top of 
soap-bubbles. 

Until a short time ago the accepted story of the in- 
vention ran somewhat as follows: Miss Carrie J. 
Everson, a school-teacher in Denver who had an as- 
sayer for a brother, one day washed some greasy 
sacks in which samples had been sent to him. Cus- 
tomary violent agitation of the water incident to wash- 
ing very dirty fabrics caused sulphide particles of ore, 
coated with grease from the bags, to float as a scum. 
Following up this occurrence, Miss Everson dis- 
covered that acid, added in small quantity to the pul- 
verized ore, greatly increased the selective action of the 
oil, and that the oiled mineral could be separated from 
the gangue by thorough agitation of the mass and by 
allowing the sulphides to float as a scum, while the 
gangue escaped at the bottom of the vessel. 

But both of these interesting stories are incorrect, 
despite the fact that a°woman really was the dis- 


108 THE STORY OF COPPER 


coverer and her last name was Everson. More ro- 
mantic than the fiction is the true story. Carrie Jane 
Billings married William Knight Everson, a physician 
of Chicago. He prospered, but was unlucky enough 
about 1878 to sink a large sum of money in a notorious 
mining promotion. Mrs. Everson had been interested 
in chemistry and, hoping to be able to retrieve some 
of the ill-fated investment, she studied mineralogy. 
During the absence of Dr. Everson in Mexico on a 
trip for his health, Mrs. Everson discovered the 
‘‘chemical affinity of oils and fatty substances for min- 
eral particles.’’ On her husband’s return he aided in 
the research, and on August 4, 1886, Mrs. Everson was 
granted a patent on the process. Dr. Everson’s health 
failed, and he died in 1889 after the family had moved 
to Denver on his account. Though his widow could not 
commercialize her patent, and though she had to be- 
come a professional nurse in order to support herself 
and her young son, she continued her investigations. 
Charles B. Hebron, a chemist, joined her in this work 
and secured some financial backing, and another patent 
was secured jointly; but this venture was not success- 
ful. Later her son, John L. Everson, with Thomas F. 
Criley, developed the process on a large scale at an 
old stamp-mill in Colorado and at other places. But 
even these extensive demonstrations did not win finan- | 
cial reward and practical use, and Mrs. Everson in 
1909 went to California with her son. Here she lived, 
forgotten by mining and metallurgical men, while law- 
suits involving millions of dollars were fought through 
the courts by later claimants to the discovery of the 
process. Not until 1915, after she had died, after fire 


FROM HARTH TO INGOTS 109 


had destroyed her cottage and the reports of her in- 
vestigations, and after her patents had lapsed, was 
she traced to California and recognized as the pioneer 
who, too early, discovered and proved a process now 
used in plants costing millions of dollars. 

At the Anaconda reduction works the sand and slime 
discarded by the earlier concentrating apparatus are 
relieved of their tiny particles of rich ore by Mrs. 
Hiverson’s process applied on a scale so extensive that, 
were she able to see it, it would astonish her. The 
slime from the de-sliming cone through which the ore 
passed before it reached the Wilfley tables is mixed 
with middling finely ground in the large ball-mills. 
When this combination flows into the flotation machine, 
it is mixed with a surprisingly small amount of certain 
kinds of oil, and then the whole is beaten into a froth 
by vigorous agitation. The metallic mineral particles 
have the lucky faculty of being able to stick to the oil, 
while the non-metallic minerals cannot. The millions 
of bubbles of the froth act as tiny balloons, and when 
the process of stirring up and aérating has been con- 
tinued for a time each air-ballon is ready to carry off 
a minute particle of valuable sulphide ore. Though 
each one may not succeed in doing so, enough rich ore 
is captured by the froth to make the process 95 per 
cent. efficient. The partiality of the froth is aided by 
the addition of small quantities of sulphuric acid. If 
the ore is ground to the almost impalpable condition of 
very fine clay it gives the best results. Flotation is a 
process in which the little particle fares best, as grains 
of ore as large as three one-thousandths of an inch 
in diameter give unsatisfactory results unless they are 


110 THE STORY OF COPPER 


mixed with much finer slimed ore. The flotation ma- 
chines are the first in the process that finally condemns 
a portion of the ore to the waste pile. The particles of 
ore that are not chosen by the froth are too poor for 
further use, and they are called tailings and are car- 
ried to the dump, while the portion of the ore concen- 
trated by the froth travels toward the roasting- 
furnaces. 

After the water has done its share in carrying the 
ore through the various concentrating processes, it 
becomes troublesome instead of useful and must be 
got rid of. By passing the concentrate from the jigs 
or tables over stationary screens or into large settling- 
tanks the excess water in the coarse and medium sizes 
of concentrate are eliminated. The fluffy mass of 
froth containing the concentrate from the flotation 
machine is still four tenths water after it has been 
allowed to settle in tanks. Then continuous filters, 
which are large revolving cylinders operating in steel 
tanks, are used to reduce the water content to only 
about one seventh. 

Only one third of the ore that entered the crushers 
at the beginning of the concentration is present and 
accounted for at the end either as roasting or blast- 
furnace concentrate. To the flotation process credit 
must be given for a large share of the good record in 
the amount of copper saved from the ore, although 
the very fine grinding of the ball-mills is needed to 
release the copper so that the flotation machines can 
separate it. Earlier than the introduction of flota- 
tion and fine grinding the amount of copper recovered 
was much lower than now, as former methods for 


FROM EARTH TO INGOTS 111 


concentrating the very fine sizes were much less effi- 
cient than flotation, and relatively coarse rich ma- 
terial was often sent to the dump. 7 

When wet methods have done their best the copper 
minerals, while more closely compacted, are not any 
closer to pure copper from a chemical point of view 
than they were in the ore. Fire is called upon to do 
its part in divorcing sulphur and the other elements 
from copper. Most of the copper ore mined in the 
world, as we have already seen, consists of sulphides 
of copper, and the oxides and sulphides combined com- 
prise about nine tenths of the world total. For this 
reason the separation of sulphur from copper 1s 
the most important objective in the pyro- or fire- 
metallurgy of copper. Usually it takes three steps 
to do this: First, part of the sulphur is driven off, 
resulting in partly oxidized ore; second, the gangue 
minerals and more of the sulphur are eliminated; 
and then the rest of the sulphur is oxidized, leaving 
crude copper. The first step is called roasting; smelt- 
ing is the term applied either to the second step or to 
the first two steps combined. The final step is usually 
accomplished by the process called converting. 

If very rich chunks of ore are being treated, such 
as those that were separated out early in the concen- 
trating process, the blast-furnace that performs the 
first two steps at one time is usually used. But if the 
fine concentrates from the tables and flotation ma- 
chines are to be treated, roasting and then smelting 
in reverberatory furnaces produces the combination 
of copper, iron, and sulphur called matte. Roasting 
and reverberatory smelting are the more modern and 


ne ie THE STORY OF COPPER 


more frequently practised methods, because the lean 
ores worked to-day produce fine concentrates and the 
reverberatory method proves more feasible and eco- 
nomical under these conditions. 

To roast a copper sulphide ore, it is heated. Some 
of the sulphur atoms united with the copper in the 
ore have a greater affinity for oxygen atoms under 
these circumstances and run off with them. Most of 
the copper is left alone. The iron sulphide usually 
mixed with the copper ore loses its sulphur but takes 
up with oxygen and is thus prepared to go off in the 
slag later on. The sulphur-oxygen combination forms 
sulphur dioxide, the noxious gas that you often smell 
when you light a match or when the coal fire smokes. 
It is the very same stuff that a voleano or a sulphur 
candle gives off. Despite its smell and the damage 
it does to vegetation, it is a valuable substance that 
ean be made into sulphuric acid, the fundamental 
chemical whose consumption, because of its variety 
of uses, measures the civilization of a country. 

Roasting copper ore is very similar to burning lime; 
in fact, the two processes are so similar that the 
roasted ore is ‘‘calcine,’’ a word derived from the 
Latin name for lime. How early in history the roast- 
ing of sulphide ores before smelting was practised 
is uncertain, although in the old Roman workings at 
Rio Tinto, Spain, there is some evidence of roasting 
the sulphide ores mined there. Certainly the step 
from lime burning to copper ore roasting would seem 
to be a simple one. But despite the fact that.the an- | 
cients understood lime burning, and calcined several 

other salts to purify them or to render them more 


FROM EARTH TO INGOTS 113 


caustic, nowhere in the remains of the old works or in 
their literature is there anything from which satis- 
factory details of sulphide ore roasting can be ob- 
tained. Not until shortly before Agricola’s time, in 
the middle of the sixteenth century, is there a specific 
account of the roasting of copper ore, and in England 


From Agricola’s ‘De Re Metallica,’ 1550 
SMELTING COPPER ORE 
A. Cakes. B. Bundles of fagots. ©. Furnaces. 


such treatment did not come into use until after 
Agricola. An insight into the methods of those times 
is given in a report of the ‘‘Doeings of Jochim Ganse’’ 
—an imported German—at the ‘‘Mynes by Keswicke 
in Cumberland, a. p. 1581,’’ wherein the delinquencies 
of the then current practice are described: ‘‘Thei 
never coulde, nether yet can make copper under XXII 
tymes passinge thro the fire, and XXII weekes doeing 


114 THE STORY OF COPPER 


thereof and sometyme more. But now the nature of 
these [X hurtfull humors abovesaid being discovered 
and opened by Jochim’s way of doeing, we can, by his 
order of workeing, so correct them, that parte of 
them beinge by nature hurtfull to the copper in waste- 
inge of its, ar by arte maide freindes, and be not onely 
an encrease to the copper, but further it in smeltinge; 
and the rest of the other evil humors shalbe so cor- 
rected and their humors so taken from them, that by 
once rosteinge and once smeltinge the ure (which 
shalbe done in the space of three dayes), the same cop- 
per ure shall yeeld us black copper.’’ Jochim pro- 
posed by ‘‘rostunge’’ to be rid of ‘‘sulphur, arsineque, 
and antimony.’’ 

Through the accidental firing of a pile of sulphide 
material roasting was probably discovered. Even to- 
day in some parts of the world this roasting in heaps 
is practised, just as the burning of lime is sometimes 
done in a similar crude fashion. Though primitive, 
heap roasting requires skill and judgment, as the proc- 
ess alms at the removal of only a portion of the sul- 
phur. Over- and under-burning must be avoided. 
Some of the heaps made are of large size, and one 
described is forty feet long, twenty-four feet wide, 
and six feet high, containing about 240 tons, burning 
for seventy days. At Mansfeld, Germany, roasting of 
copper ore is practised to remove not sulphur but 
bituminous matter, which is undesirable. An improve- 
ment over heap roasting is the use of stalls or rec- 
tangular brick chambers in which to carry on the op- 
eration, but, aside from the opportunity of draft regu- 
lation and control of the burning, it is little superior 


FROM EARTH TO INGOTS 115 


to heap roasting. ‘To-day, just as machines are do- 
ing the work of many other cruder and earlier proc- 
esses, copper ore roasting is accomplished in furnaces 
into and out of which the ore flows continuously. In 
the Anaconda reduction works, cylindrical furnaces of 
the McDougall type with several hearths, one above 
the other, substantially built of brick and inclosed 
in a steel plate casing, are used for this process. 
The concentrate is automatically fed to the top hearth, 
from which it begins a journey downward. Two large 
plow-like arms attached to a shaft in the center of 
the furnace move the concentrate from the circum-. 
ference to the center of the hearth, where it drops 
through an opening to the next hearth. Two similar 
arms here pick the ore up and conduct it to the cir- 
cumference for a repetition of the cycle on the lower 
hearths. Hot gases come up from the lower hearths, 
where concentrate introduced earlier is roasting in 
its own heat. This ability of the concentrate to roast 
itself is due to the large percentage of iron pyrite that 
it contains. Only when a furnace is being put into 
operation is there need of outside heat from coal or 
wood. The rabble arms stir the concentrate on its 
downward path from hearth to hearth, exposing fresh 
surfaces of the charge to the hot gases, and they would 
warp if they were not protected by a continuous cir- 
culation of water on their interiors. When the ore 
passes from the bottom of the roasting furnace it 
contains only 8 or 9 per cent. of sulphur instead of the 
30 to 33 per cent. that it had when it entered. 

The success of the next operation, smelting, de- 
pends upon copper’s affinity for its earlier associate, 


116 THE STORY OF COPPER 


sulphur. The roasted ore consists of a mixture of sul- 
phides of copper and iron, iron oxide, and metallic 
copper, together with silica and alumina which have 
been purposely left in the ore during concentration 
because of their aid in the smelting process. Lime, 
which will aid in forming a more fusible slag, is also 
present, as it has been added to the ore during the 
roasting process. This mixture is charged upon the 
hearth of the reverberatory smelter and bombarded 
by heat radiated from the countless particles of in- 
candescent carbon in the coal-dust flame. The result 
is the formation of matte, slag, and the gases that are 
given off. In the matte the copper and a large part 
of the sulphur are contained, while the slag is made 
up of the iron, silica, alumina, and lime. The rather 
complex reactions are brought about simply by the ad- 
dition of heat to the charge; no complications are in- 
troduced by the addition of fuel or blasts of air as in 
the blast-furnace. When melted, copper has greater 
affinity for sulphur than have the other metals, and for 
this reason during the smelting the copper oxide of 
the charge relieves the iron sulphide of its sulphur and 
gives it its oxygen. As the copper does not need 
as much sulphur as the iron, sulphur dioxide gas 
is also formed. In all, up the flue goes more than a 
quarter of the sulphur in the smelting mixture. The 
iron oxide becomes part of the slag, and the copper 
sulphide with the remaining iron sulphide combine to 
form the matte. Asa result, the matte, being heavier, 
settles to the bottom, while the slag floats on top. A 
sudden drop into a stream of cold water is the fate 
of the slag as it flows continually out of the furnace; 


FROM EARTH TO INGOTS Ai 


after this cool treatment it is sent to the dump. 
Whenever enough of the precious matte accumu- 
lates, the bottom of the furnace is tapped and the 
liquid taken in large steel ladles to the converter. 
The smelting process results in a further richness of 
copper; the matte contains 38 per cent. of the red 
metal as contrasted with the roasted ore, which con- 
tained only 9 per cent. From each hundred tons of 
charge, sixty-seven tons of slag and twenty-four tons 
of matte are produced. Reverberatory furnaces have 
erown with the copper industry; the modern reverber- 
atory furnaces have hearths twenty feet wide and. 
143 feet long, sixteen times the area of the Anaconda 
furnaces constructed in 1884. Since that early day 
not only has the size of the furnaces increased but 
the methods of charging and firing the furnaces have 
been improved. Where automatic conveyors now feed 
the furnaces, men once had to brave poisonous sul- 
phur fumes during hand feeding; instead of being 
heated from grate fires, powdered coal sprayed directly 
upon the hearth produces the temperature needed. 
Let us return to the coarse, rich ore that we left 
shortly after the beginning of the reduction process, 
and see how it is turned into matte. The ore is smelted 
in blast-furnaces, steel structures about fifteen feet 
deep, only about five feet wide, but in length ten to 
fifteen times their width. To protect them against 
the intense interior heat, the walls are jacketed, and 
a constant stream of water reduces the temperature 
that otherwise might cause disaster. Into these fur- 
naces the coarse ore, broken limestone rock, and a small 
quantity of coke are introduced. When the charge 


118 THE STORY OF COPPER 


is ignited and blasts of air supplied by great rotary 
blowers are forced into the bottom through numerous 
tuyere pipes, the coke burns, together with three fifths 
of the sulphur in the ore, and the combined heat 
brings about reactions very similar to those in the 
reverberatory furnace. Matte and slag are formed, 
and those two products collect in a shallow pool in the 
bottom of the furnace and flow out through water- 
jacketed spouts into large settlers. In this large vat 
the matte separates to the bottom just as it did in 
the reverberatory furnace, and the slag passes through 
an over-flow-spout on its way to the waste heap. 
Smelting can be carried on without the aid of any 
fuel other than the sulphur contained in the copper- 
bearing iron pyrites of the ore if the ore is sufficiently 
rich in pyrites, and when this is the condition the 
process is called ‘‘pyritic’’ smelting. 

Although the blast-furnace may produce matte in 
one operation while both the roasting furnace and 
the reverberatory furnace are necessary in the process 
usually used now, it does this because it combines 
the functions of both roasting and smelting. It oxi- 
dizes and smelts simultaneously, and also uses the 
heat generated by the oxidation of the sulphur and 
iron. The blast-furnace shaft can be roughly divided 
into two zones, the preheating and the fusion zones. 
In the first the silica remains unaltered; the chalco- 
pyrite has one fourth of its sulphur driven off as 
vaporized sulphur and becomes a different mixture of 
copper and iron sulphides; and the pyrite, which is the 
iron sulphide mixed with the copper ore, loses about 
half of its sulphur and becomes an iron sulphide con- 


FROM EARTH TO INGOTS ty 


taining less sulphur. In the lower zone the chaleo- 
pyrite mixture melts as soon as its temperature be- 
comes high enough; the sulphur remaining in the py- 
rite is partly burned to sulphur dioxide by the oxygen 
in the air-blast; and the rest of the sulphur joins the 
iron and copper to form matte. Thus it may be seen 
that the blast and reverberatory methods, which may 
seem to be different if you see both of them in opera- 
tion, are very much alike so far as their chemistry 
and physics are concerned. When a mine produces 
partly oxide and partly sulphide ore, the oxide ore 
can be mixed with the sulphide to produce the effect. 
of roasting without the trouble, and the roasting step 
necessary with all-sulphide ore can be abandoned. 
Fuel economy is partly responsible for the more 
prevalent use of the reverberatory furnace in prefer- 
ence to the blast-furnace; despite the low thermal 
efficiency of the reverberatory furnace, ranging from 
5 to 20 per cent., the utilization of the waste heat 
for steam-making and power production makes the 
reverberatory furnaces more economical in most in- 
stallations. At Anaconda the blast-furnaces stand 
idle, and are not operated unless the ore production 
exceeds the capacity of the batteries of reverbera- 
tories. The size of the present-day ore particle is 
another cause of the decline of the blast-furnace. So 
long as the ore is rich and large, the blast-furnace does 
satisfactory work. Attempts to use the fine concen- 
trate of the tables and flotation process in the blast- 
furnace are literally blasted; the powdered ore joins 
the gases, goes up the flue, and, unless specially taken 
eare of, settles over the countryside. Only chunks of 


120 THE STORY OF COPPER 


ore can stand this rough treatment; the ‘‘fines’”’ give 
up their copper more readily if they are subjected to 
the gentle treatment of the reverberatory furnace. 

There is one interesting thing about both processes 
which may have been noticed. Unlike the conditions 
in the blast-furnace producing iron, the carbon of the 
coke or coal flame does not play anywhere near so 
important a part in the reactions in the copper re- 
duction processes. This fact makes it possible to 
look forward to the use of some other source than coal 
for the heat required by the process. Tests have been 
made in numerous instances which show that from 
an operative point of view the use of the electric 
furnace for the production of copper matte is a suc- 
cess either by roasting and reverberatory methods 
or by the blast-furnace. Practical use of electrical 
methods is a matter of economic and mechanical per- 
fection. Where coal is scarce, very soon we may ex- 
pect the abandonment of use of stored-up sunshine of 
the Carboniferous era and the substitution of white 
coal that runs down to the sea hour a hour whether 
we use it or not. 

When matte is obtained either from the reverbera- 
tory or the blast-furnace, the silica, alumina, and part 
of the sulphur that were in the ore have been elimi- 
nated, and the red metal desired is still united with 
sulphur and iron. Spectacular methods are used to 
separate the copper from the sulphur and iron, which 
are literally burned out. 

Into a large pot-like furnace about sixty-five tons of 
molten matte are poured. Through pipes entering the 
bottom of the furnace compressed air under moderate 


FROM EARTH TO INGOTS 121 


pressure is introduced. Varicolored flames belch forth 
from the mouth of the converter, as the furnace is 
called, and the sulphur and the iron are burned. Sul- 
phur dioxide goes up the flue, and the iron oxide left 
joins with the raw ore containing silica and alumina 
that have been introduced into the converter with the 
matte so that iron slag can be formed. During this 
first part of the process the copper content has been 
increased from the 45 to 50 per cent. in the matte to 
about 78 per cent. When the slag has been poured off 
by tilting the whole converting furnace, the blowing 
is continued until virtually all the sulphur is burned 
off, and the metallic copper, freed at last from bondage 
with other elements, sinks to the bottom of the fur- 
nace, carrying alloyed with it silver, gold, and various 
other valuable or troublesome metals. It takes about 
five hours for a converter to change matte into cop- 
per. The experienced eye of the operator determines 
when the different stages of the process arrive at 
completion. The size and color of the flame varies; 
the color changes from yellow, through orange and red, 
to blue. Another sign that the converter foreman 
watches is the way in which small particles of slag, 
matte, or copper, thrown up by the air-blast, act when 
they strike the hood at the lower end of the flue into 
which the converter gases pass. 

An Anaconda converter complete weighs about three 
hundred tons, it must be able to tilt quickly and ac- 
-eurately and elevate tons of molten metal with as much 
ease as a foundryman pouring brass to make a small 
casting. T'wo pairs of massive steel rollers carried on 
substantial foundations support the converter, and 


122 THE STORY OF COPPER 


a large electric motor provides the power for its 
movements. On its inside, the steel shell is thickly 
lined with magnesite brick. Though you would not 
realize it from looking at it, this basic lining is now 
saving much money wasted by use of the acid linings of 
a few years ago. Before the magnesite lining was 
perfected, the lining was also a part of the charge. 
Ore, high in the acid-minerals silica and alumina, was 
ground together with some of the clay-like slime of 
the mechanical concentration process and tamped into 
the shell for lining. Hach charge of matte, in being 
converted, used a large layer of this lining as the iron 
of the matte united with the silica and alumina to form 
slag. After two or three blows the whole process of 
lining had to be repeated. Now, in addition to a lin- 
ing that will not enter into the converting, layers of 
magnetite, a combination of iron oxides, and a further 
skin of alumina are formed upon the magnesite, by the 
slag, and theoretically the hning lasts forever. In 
practice, of course, the wash of the molten materials in 
the converter gradually wears it away, and if, because 
of accident or lack of matte to be treated, the converter 
must be allowed to cool down, some of the lining will 
be flaked off by contraction. 

The slag produced in the converter, unlike that from 
the reverberatory and blast-furnaces, is too rich in © 
copper to be sent to the dump, and its metal is saved 
by treatment in the blast or reverberatory smelting 
furnace. The copper while still molten is sent to the 
refining furnaces, built on the reverberatory plan, 
where remaining small amounts of iron, sulphur, and 


FROM EARTH TO INGOTS 123 


slag are removed. In imitation of the converters, 
compressed air not only assists this iron and sulphur 
to enter the slag but the blast also oxidizes some of 
the copper into cuprous oxide. This oxide mostly 
melts and diffuses through the metallic copper, and, 
readily parting with its oxygen to the impurities, 
further facilitates their complete oxidation. When 
the blast has virtually eliminated the impurities, the 
molten metal contains a great deal of dissolved oxides 
which must be reduced. Ends of green tree-trunks 
or poles are forced under the surface of the molten 
charge, and the large quantity of gases generated by. 
the dry distillation of the poles reduces the oxide and 
brings the copper to a high degree of uncombined 
purity. At this point the copper still contains the 
valuable metals and also impurities that prevent its 
use for electrical purposes. It is run into molds and 
turned into ‘‘anodes’’ weighing about five hundred 
pounds. These large thick sheets of copper leave for 
the electrolytic refinery where more experiences await 
them. 

Only since 1878 has the converter been used, and 
to-day in many places the old method is practised of 
roasting the matte and then smelting and refining the 
oxidized product by repeated fusions. In the cruder 
and earlier processes the basic reactions and methods 
do not differ greatly from modern practices, though 
much more work and an inferior product are the 
penalty attached to the less advanced methods. Be- 
fore the Christian era the refining of copper by re- 
peated fusion was practised, and by Agricola’s time 


124 THE STORY OF COPPER 


roasting of matte and the subsequent refining of the 
oxidized copper were the usual methods of obtaining 
metallic copper. 

When we compare the immense mines of to-day with 
the pits of yesterday, modern furnaces with the crude 
contrivances of the past, nothing is more striking than 
a comparison of the speed of the reduction processes. 
When ore had to be heap-roasted and the matte re- 
peatedly roasted in stalls, it took four months to 
achieve copper. Now sulphide ore can be fed into 
the blast-furnace in the morning, the matte sent di- 
rectly to the converter, blown into copper, and shipped 
as anodes in the evening. 

But valuable by-products as well as time are saved 
in modern reduction works. Formerly sulphur fumes 
and gases were poured forth into the air to poison the 
vegetation and the surrounding country; now Cottrell 
precipitators electrify the smallest particles of fume 
and save them to be turned into valuable, civilization- 
producing sulphuric acid. The dust that escapes from 
the furnaces are caught by the precipitators, or large 
settling-chambers, and the heat that formerly went 
into the air is now used to run engines or warm build- 
ings. | 

We have traveled through the reduction processes 
at Anaconda, and have seen how a piece of sulphide 
copper ore might be treated in other places and at 
other times. Because a copper oxide ore is virtually 
the same as a sulphide ore that has been given a thor- 
ough roasting, and because oxide and sulphide ores are 
often treated together, we also know the experiences 
that oxide ore must endure to become metallic. There 


FROM EARTH TO INGOTS 125 


is another way in which copper ore can escape the 
bondage of the earth and become metal, and that is by 
the wet process. Much low-grade ore is exploited by 
using this comparatively modern method. But let us 
first see how uncombined metallic native copper is 
prepared for man’s use. 

Compared with the processes that a sulphide ore 
must pass through, the native copper ores of Michigan 
undergo a very simple process to become usable 
copper. One to 3 per cent. copper with some native 
silver are contained in the conglomerate and amygda- 
loid ores. These ores go through a concentration simi- 
lar to the first steps that sulphide ores take. Crush- 
ers, steam stamp-mills, and Hardinge mills crush them, 
and then they dance on jigs and tables until a 
coarse concentrate containing about 60 per cent. cop- 
per is produced. This rich concentrate, joined by the 
lumps of mass copper that are often found in the 
Michigan mines, is charged into a reverberatory fur- 
nace and simply melted down without any fluxes; the 
slag is skimmed off as it is formed. In some cases 
the molten copper is sent to another furnace for re- 
fining, but often it is purified in the same furnace. 
The impurities in this native copper are removed by 
oxidation and reduction and by contact with fresh wood 
similarly to the copper from the converters. After 
this fire refining, the copper is cast into commercial 
shapes for marketing; only that portion high in silver 
content achieves the distinction of being sent through 
electrolytic refineries. The best ‘‘Lake’’ copper, as 
the copper made from Michigan ores is called, is 
usually so pure that it compares favorably with 


126 THE STORY OF COPPER 


electrolytically purified copper and it is suitable for 
use for electrical work. 

One general method of extracting copper from its 
ores depends upon the solubility of copper in dilute 
acids when it is combined with other elements. Water, 
acids, iron, and electricity, instead of heat, are the 
reagents that secure the separation; the processes are 
carried out in large tanks instead of immense furnaces. 
Iixtraction of copper by the wet method is usually ac- 
complished in three steps: First, the copper if nec- 
essary is converted into a soluble form; second, the 
soluble copper salt is dissolved out and taken into 
solution; third, the copper is precipitated from the 
solution as the metal. 

A story is told at Butte of how one of the simplest 
and most important of the wet processes of copper 
recovery originated. The waste water from one of the 
mines flowed through ‘‘Jim’’ Ledfad’s back yard. 
One day he threw some tin cans in the little gully 
made by the mine water, and the next morning he was 
surprised to find that they had turned to a slush of 
copper. An assay showed that the metal was 98 per 
cent. pure. Jim kept his secret well and signed up a 
year’s contract for all the water that came from the 
mines. Before his twelve months of opportunity were 
up, he had made ninety thousand dollars out of his 
discovery. 

Jim’s process is used at Butte to-day and at vir- 
tually every other sulphide copper mine in the world 
where waters have a chance to flow. The sulphide ores 
are acted upon by the oxygen in the air and in the 
water and are changed to copper sulphate. This com- 


FROM EARTH TO INGOTS 127 


pound is easily soluble in water and runs off or is 
pumped out of the mine in the troublesome water. If 
_ this water comes into contact with iron, such as is con- 
tained in scrap tin cans, the sulphate radical, because 
of its chemical affinity, drops the copper, leaving it as 
such, and unites with the iron. This exchange occurs 
because iron is more positive than copper in the 
electro-chemical series. When copper and iron are 
brought together there is an electrifying time, a real 
current is set up, but the direction of the current and 
the result of the precipitate encounter over the sul-— 
phate is predestined by the properties of the two 
metals. In this case, though iron wins the sulphate, 
copper is released to do its work in the world as a free 
metal. At the Copper Queen mine at Bisbee, Arizona, 
as. well as at the Butte mines, special plants have been 
installed to recover the copper in the mine water. The 
precipitation of copper upon iron in this way is known 
as ‘‘cementation,’’ and the product is called ‘‘cement’’ 
copper. Despite the large number of scrap tin cans 
produced as a by-product of civilization, the supply is 
not large enough for this use. Scrap iron is used 
where it can be obtained, but crude pig-iron is the 
standard source of the metal used to precipitate 
copper. 

At Rio Tinto, Spain, there are about twenty-five 
million tons of copper sulphide ore that are waiting 
for the weather to change their copper into the form 
that can be dissolved and precipitated by iron. These 
ores consist of massive pyrites containing about 3 per 
cent. copper. The ore is built into massive heaps of a 
million tons or more, arranged with suitable venti- 


128 THE STORY OF COPPER 


lating flues and chimneys, and it is sprayed with water 
to promote the atmospheric oxidation of the pyrites. 
By an interaction of the iron sulphates formed with 
the copper sulphides, soluble copper sulphate is finally 
obtained and leaches out. Ferrous sulphate is first 
formed, which slowly oxidizes to ferric sulphate and 
reacts with the cuprous sulphide to form soluble cop- 
per sulphate and insoluble cupric sulphide. The lat- 
ter is again oxidized to cupric sulphate by the ferric 
sulphate and the atmospheric oxygen. The solution 
draining from the heap contains both ferric and cupric 
sulphates, and this iron sulphate is reduced to the 
ferrous sulphate by passage through a layer of fresh 
ore, thus preventing unnecessary waste of the iron 
used in precipitating the copper from the cupric sul- 
phate solution. It takes a period of four years to 
complete the process of extraction of a heap of ore. 

Before the flotation process was adopted at Butte, 
tailings containing thirteen pounds of copper to the 
ton, three times as much as is contained in the tailings 
produced now, were sent to the dump. Now this 
‘‘waste’’ is re-mined and the copper is extracted by 
leaching. The spectacle of one generation prizing 
what the past has thrown away is too frequent to be 
odd. Even Agricola, who in the fifteen hundreds 
wrote the first detailed work on metallurgy, tells of 
men who made an independent business of working 
over the tailings of mine dumps. Now some of the 
dumps created only a few years ago are looked upon 
by the operators in the same way that a coal-hunting 
pickaninny regards the ash-pile of a careless engine- 
tender. They are in the same class with the mines 


FROM EARTH TO INGOTS 129 


themselves. Many Michigan mines are reworking at 
a profit their tailings of the past, and, as metallurgi- 
cal processes improve and smaller and smaller amounts 
of copper can be profitably extracted, every dump will 
become available for exploitation as a new copper 
mine. 

Water containing a small amount of lime carbonate 
has run over the Butte tailings and changed part of 
the sulphides to carbonates, but most of the ore has 
been unchanged. In the extracting process the tail- 
ings are first roasted to change copper sulphide into 
oxide and then placed in large lead-lined tanks, one 
thousand tons at a time. Seventy thousand gallons 
of fresh water, thirty-five tons of commercial sul- 
phuric acid, and fifteen tons of common salt are added. 
This solution, heated, leaches downward through the 
roasted ore, and the percolation is repeated until all 
metal possible has been dissolved. The sulphuric acid 
dissolves the copper, and the main purpose of the salt 
is to dissolve the silver, which would not be taken up 
by the acid alone. The salt also increases the speed 
of extraction of the copper. Iron is used to precipl- 
tate the copper and silver, and as the cement copper is 
only 60 per cent. pure it is smelted in the reverbera- 
tory furnace. 

Much the same process, without the roasting, is ap- 
plied to part of the upper and oxidized ores at the 
copper mine at Bingham, Utah. Sulphuric acid is 
the most frequently used solvent in hydrometallurgi- 
cal processes, and in some cases the ore itself produces 
the acid that leaches it. If a sulphide ore is roasted 
preliminary to leaching, the sulphur dioxide can be 


130 THE STORY OF COPPER 


saved and converted into sulphuric acid. Though most 
of the copper of the world is locked up with sulphur, 
this element seems perfectly willing to aid man in ob. 
taining the red metal. In smelting, sulphur often fur. 
nishes virtually all the heat; in leaching, it makes the 
acid that carries off the copper. | 

Some substitute for iron in precipitating the cop- 
per from solution has been searched for. Hydrogen 
sulphide, the evil-smelling gas that is present in de- 
cayed food, particularly bad eggs, not only performs 
this function well but rejuvenates the sulphuric acid 
at the same time and prevents the loss of both acid and 
iron that occurs when the useless ferrous sulphate 
runs away as the result of iron precipitation of copper 
solutions. But this gas is difficult to produce and 
handle in large quantities, and the process is not used 
commercially. 

Electricity that hauls and lifts the ore, that jigs it, 
that may smelt it in the future, can virtually substi- 
tute for iron in removing copper from solution. It 
seems probable that much of the world’s copper which 
must be produced from lean ores will be transformed 
from ore to refined marketable copper in only two es- 
sential steps: solution in acid, and electrical precipi- 
tation from solution. If the ores are sulphides, they 
will have to have a preliminary roasting. Even the 
process of electrolytic refining of which we shall tell 
later, will be included in this tabloid process of leach- 
ing. 

Such a process is now in operation at the second 
largest known copper deposit in the world, that at Chu- 
quicamata, Chile. The principal mineral is an oxy- 


FROM EARTH TO INGOTS 131 


sulphate known as bronchantite, which, though only 
partially soluble in water, is readily dissolved in weak 
sulphuric acid. Salt, sodium chloride, is also present 
along with some atacamite, or copper oxy-chloride. 
About four hundred million tons of ore have already 
been proved, and it averages over two per cent. copper. 
Steam-shovels mine the ore; then it is crushed, and 
sent on belt conveyors to large leaching tanks that each 
take a charge of ten thousand tons. Because chlorides 
are present in the ore, the acid leaches out cupric 
chloride as well as sulphate. The chloride must be re- 
moved before electrolysis; otherwise the chlorine gas 
would be liberated at the anodes and chances of gas at- 
tacks would be good. The cupric chloride is changed to 
cuprous by contact with metallic copper, and as cup 
rous chloride is insoluble it is filtered out. In electro- 
lyzing the remaining sulphate solution an inert anode 
must be used, so that copper is carried by the electric 
current from the solution and deposited on the cathode. 
Because Chuquicamata ores are mostly sulphates, the 
electrolysis produces more sulphuric acid than can be 
used; no acid has to be imported and, like the pyritic- 
ally smelted ores and roasted ores leached in their 
own acid, they fall thus partly into the self-reducing 
classification. 

Application of wet reduction of copper, has one 
serious disadvantage if the ores run high in gold or 
silver, as these precious metals can not be recovered 
by usual methods. But the leaching process is the 
hope of lean ores for future conversion into valuable 
sources of copper. Other hydrometallurgical methods 
will undoubtedly be devised; some that are at present 


132 THE STORY OF COPPER 


on paper or in laboratories will be applied. A com- 
bination of the flotation process of concentration with 
the leaching process promises to make available ore 
that is even leaner than that now exploited. 

As copper has contributed so vitally to the develop- 
ment of the electrical age that we are now in, it 
seems only just that electricity plays such an important 
part in the preparation of copper for the work of the 
world. Because copper is used in electrical work, it 
must be pure; it can be made pure because it can be 
refined electrically. 

To-day more than five sixths of the copper produced 
in the United States is s.nt through the electrolytic 
refining process. Blister copper from the converters, 
black copper from the furnaces, and even the pure Lake 
copper from Michigan enter the refineries and come out 
of the melting-pot without distinction of class, and of 
asingle purity. First of all, copper is refined to make 
it pure, but there is a secondary reason that at times 
becomes primary. In some cases copper that has come 
through the fire refining processes will pay its own re- 
fining costs many times over on account of the valu- 
able metals that it contains. Gold, silver, platinum, 
and palladium are concentrated in the copper and are 
separated during electrolysis. Millions of ounces of 
these metals that otherwise would be lost are recovered 
in this way. Some of the Lake coppers that are 
sufficiently pure for electrical work without refining 
are sent through the process only because there is 
enough silver in them to make it profitable.. If cop- 
per contains even as little as ten dollars’ worth of 


FROM EARTH TO INGOTS  _133 


precious metals to the ton, it will find a journey through 
the refinery worth while. 

When copper enters the refinery it is melted in re- 
verberatory furnaces and cast into anodes, if it is 
not already in that form. Then it is ready for electrol- 
ysis. This is a simple operation in principle, but 
it is carried out on a large scale. At large refineries, 
such as those at Perth Amboy, New Jersey, Baltimore, 
Maryland, or Great Falls, Montana, there are thou- 
sands of lead-lined wooden tanks in lengthy buildings, 
each containing two sets of copper plates immersed in 
blue liquid. Heavy copper bus-bars carrying electric 
current lead to the plates. Electrolysis consists of 
feeding in direct current to the impure copper positive 
plates, called anodes, and thus inducing the copper to 
purify itself by dissolving in the electrolyte of copper 
sulphate and sulphuric acid and then depositing on the 
other or negative plates, called cathodes. The cath- 
odes are mere paper-thin sheets of copper when the 
process begins but they finally get thick and fat. at 
the expense of the impure anodes. The various im- 
purities virtually all refrain from joining with the 
copper on the cathode. Nickel, cobalt, iron, mangan- 
ese, zine, lead, and tin are electropositive to copper and 
hence dissolve at the anode and concentrate in the 
solution. The precious metals, gold, silver, and plati- 
num, with selenium and tellurium, are electronegative 
and do not dissolve but drop down to the bottom of 
the tank and form what is called ‘‘anode slime.’’ The 
impurities in the form of compounds of copper with 
oxygen, sulphur, tellurium, and selenium also form 


134 THE STORY OF COPPER 


part of the anode slime. As arsenic, antimony, and 
bismuth stand near copper in their electrochemical be- 
havior, they are partly dissolved and may be deposited 
at the cathode. It requires about a month for an 
anode weighing five hundred pounds to be dissolved 
to such an extent that its remains are sent back to the 
anode casting furnace. During this time the con- 
stantly flowing current of heavy amperage but low 
voltage has built up three sets of cathodes each weigh- 
ing about 135 pounds. To aid the action the copper 
sulphate electrolyte is kept in constant circulation by 
pumps and is maintained at a temperature near 135 
degrees Fahrenheit. At intervals the electrolyte is 
purified and the metallic salts that it has acquired are 
erystallized out and refined. Most of the copper sul- 
phate or bluestone of commerce is obtained from the 
electrolyte of the refineries and nearly seven tenths of 
1 per cent. (7,823,000 pounds in 1920) of the domestic 
refined copper are used this way. The anode slime is 
refined and the gold and silver sent to the mint or 
placed on the market. Precious platinum and pal- 
ladium are sold as sponge, and the selenium may go 
to make photo-sensitive cells. For tellurium, which 
is the weak sister of sulphur, the industrial world has 
up to the present time been able to find little use. 
The cathodes are very nearly pure copper—99.98 per 
cent. pure. But they are not in shape so that they 
can be handled easily in commerce or in the wire, pipe, 
and sheet mills, and for this reason they must be 
melted. This would seem to be an easy matter, but 
during the fusion in the reverberatory furnace the cop- 
per tends to revert to impurity by reason of the in- 


FROM EARTH TO INGOTS 135 


fluence of the sulphur found in the coal, as well as 
that of the oxygen in the air. It succeeds partly, and 
the melting process has also to become a fire refining, 
using the air-blast, poling, and other steps that the cop- 
per had experienced before its cleansing treatment 
with electricity. And despite all precaution it 
emerges from its melting less pure than it entered, 
though it easily surpasses non-electrolytic copper. <A 
representative analysis of refined electrolytic copper 
would give results that would be approximately as 
follows: 

Copper, 99.95000 per cent.; silver 0.00100 per cent. ; 
gold, 0.00001 per cent.; sulphur, 0.00300 per cent.; oxy- 
gen, 0.0300 per cent.; iron, 0.0020 per cent.; nickel, 
0.0015 per cent.; arsenic, 0.0015 per cent.; antimony 
0.0020 per cent.; aluminum, 0.00100 per cent.; phos- 
phorus, trace; lead, 0.00200 per cent.; bismuth, trace; 
selenium, 0.00050 per cent.; tellurium, 0.00050 per cent. 

The molten copper of the refining furnace is cast 
into commercial shapes. An automatic machine pours 
the metal into copper molds, tips the cast copper into 
a cooling bath of water, and sends the bars, slabs, 
cakes, and billets on an endless belt to the weighing 
scales ready for shipment. As copper is used in many 
industries, the form in which it is placed on the market 
depends upon the use to which it is to be put. Ingots 
of copper are used primarily where the copper has to 
be remelted in crucibles either for the making of cop- 
per castings or the manufacture of alloys such as brass 
and bronze. They have a shape that will readily fit 
into crucibles, and are about ten inches long, weighing 
from sixteen to twenty-two pounds. Ingots have one 


136 THE STORY OF COPPER 


or two notches so that they can be broken easily in 
two or three pieces if necessary. Wire bars, the most 
popular form of refined copper, are used at mills 
as the material for the drawing of copper wire. These 
bars are cast with pointed ends in order that they 
may easily enter the first set of rolls. The size and 
weight of wire bars vary greatly, the length from 
thirty-nine to one hundred inches and the weight from 
135 to 770 pounds. Slabs and square cakes of various 
sizes are used for rolling purposes, where sheet copper 
is the final product; and their size depends upon the 
size of the finished product. Circular cakes are used 
for the manufacture of large seamless cylindrical prod- 
ucts such as hot water heaters and tanks. Billets are 
used for the manufacture of seamless copper tubing 
of all sizes, and during the war were used extensively 
in the manufacture of the smaller size of shell bands. 
Billets vary from three to eight inches in diameter, and 
from fifteen to fifty inches in length, and their weight 
varies from seventy-five to six hundred pounds. 

A small amount of copper, mostly from Arizona, 
is so pure and contains so little precious metal that 
it may be sold for casting purposes directly after fire 
refining’; otherwise all of America’s copper, excepting 
that of northern Michigan passes through a dozen re- 
fineries. Half of these, the half with the largest pro- 
duction, are on the Atlantic tide-water, and only three, 
those at Great Falls, Montana, Tacoma, Washington, 
and Trail, Canada, are west of the Great Lakes. The 
Eastern refineries are not only more numerous but have 
greater producing capacity. The American Smelting 
and Refining Company refinery at Baltimore is cred- 


FROM EARTH TO INGOTS 137 


ited with a capacity of 720,000,000 pounds of copper 
a year, which exceeds by more than 100,000,000 pounds 
the total refinery output for the whole country in 1921, 
an off year for copper. The Nichols Copper Company 
at Laurel Hill, New York, has a capacity of 500,000,000 
pounds, and the Raritan Copper Works, Perth Amboy, 
New Jersey, controlled by the Anaconda, has a capac- 
ity of 480,000,000 pounds. Both the American Smelt- 
ing and Refining Company plant at Maurer, New Jer- 
sey, leased by Phelps-Dodge, and the United States 
Metals Refining Company, Chrome, New Jersey, have 
capacities of 240,000,000 pounds, and the Great Falls, 
Montana, refinery of the Anaconda Copper Mining 
Company and the American Smelting and Refining 
Company at Tacoma, Washington, both have capacities 
of sightly more than 200,000,000 pounds a year. The 
electrolytic refinery of the Calumet and Hecla Mining 
Company at Hubbell, Michigan, is rated at 60,000,000 
pounds. It is estimated that the tonnage of the fire- 
refined copper from the Michigan district is about one 
sixth of that produced by electrolytic methods. When 
compared with American refineries, those of other 
countries seem insignificant. KEngland, Wales, New 
South Wales, Queensland, South Australia, and Chile 
each have one, while Japan has eight, Russia three, 
and Germany one. 

The geographical distribution of the smelting and 
reduction plants of the country is entirely different 
from that of the refineries; it more nearly tallies with 
that of the mines. It is decidedly uneconomical to 
transport worthless gangue a great distance, and for 
this reason the concentration processes up to the point 


138 THE STORY OF COPPER 


at which metallic copper is secured must be carried out 
near the place where the ore is taken from the earth. 
It is, however, profitable to refine away from the mine. 
As most of the copper must travel east in order to be 
manufactured and as the coal for generating the elec- 
tricity used in refining is also near the Atlantic coast, 
it is more economical to carry on the refining of a 
large portion of the copper on the EKastern seaboard. 
More than fifty copper smelting works are scattered 
through the mining districts of North America, and 
virtually every one has at least one blast-furnace or 
reverberatory furnace and one converter, although 
some of the smaller ones ship matte to the larger 
smelters. 

About two dozen companies produce most of the 
copper that is refined in the United States. The con- 
trol of production rests in four main groups: the 
companies operating in the Lake copper region in 
Michigan; the Anaconda group operating in Montana; 
the Guggenheim interests, principally the American 
Smelting and Refining Company; and the Phelps- 
Dodge group, chiefly concerned in production in Ari- 
zona. Chief among all the many producers is the An- 
aconda Copper Mining Company, which now owns 
mines, refineries, and fabricating shops. When it 
bought early in 1923 the Chile Copper Company, owner 
of the great deposits at Chuquicamata, Chile, and 
placed it beside the American Brass Company, the 
largest fabricating plant for brass and copper prod- 
ucts, which it acquired shortly before, it became 
second to the United States Steel Corporation in the 
metal world. Incidentally, it is interesting to know 


FROM EARTH TO INGOTS 139 


that the purchase of the Chile interests required about 
$75,000,000 cash and is said to rank as the largest 
single item of financing by a mining company that has 
ever been carried out in any country. Prominent 
among the copper producers are also the Arizona 
Commercial Mining Company, Braden Copper Com- 
pany, Calumet and Arizona Mining Company, Calumet 
and Hecla Mining Company, Chino Copper Company, 
Copper Range Company, East Butte Copper Mining 
Company, Green Cananea Copper Company, Inspira- 
tion Consolidated Copper Company, Kennecott Cop- 
per Corporation, Miami Copper Company, Mother 
Lode Coalition Mines Company, Nevada Consolidated 
Copper Company, New Cornelia Copper Company, 
North Butte Mining Company, Old Dominion Com- 
pany, Phelps-Dodge Corporation, Ray Consolidated 
Copper Company, Shattuck Arizona Copper Company, 
United Verde Extension Mining Company, Utah Cop- 
per Company, and Utah Consolidated Mining Com- 
pany. 

Perhaps you would like to know what is done with 
the metal that this extensive industry produces. Sup- 
pose we take the year 1923, which is more typical than 
the two succeeding years, although even it is not an al- 
together typical period. The total production of re- 
fined copper in the United States for 1923 is given as 
2,248,000,000 pounds. Of this 1,455,000,000 is new 
copper produced from domestic sources, and 683,000- 
000 pounds is from foreign sources, although a large 
portion of it is refined in this country. The rest of 
the production is made up of secondary copper, which 
amounts to 130,000,000 pounds during the year. Not 


140 THE STORY OF COPPER 


only do the large refineries rejuvenate copper, brass, 
and other alloys that have seen one round of service 
but numerous small plants in all parts of the country 
make a business of remelting and purifying old scrap 
copper and alloys. About half of the secondary cop- 
per is produced from new scrap from copper and brass 
manufacture. In 1923 the domestic consumption of 
new copper is recorded as 1,305,000,000 pounds, but to 
this must be added the 130,000,000 pounds of available 
secondary copper. Imports of metallic copper are 
included in the figure for production from foreign 
sources; and we usually bring into the country about 
one third to one half as much metal as we consume 
from new domestic sources. But an amount larger 
than our imports is exported; it usually equals the 
domestic consumption of new copper, although in 1923 
it only amounted to 773,000,000 pounds. In reality 
more copper than this is sent to other lands, as this 
figure includes only the unmanufactured copper ex- 
ports, and the amounts in manufactured articles sent 
overseas is unknown. If these figures are a little dif- 
ficult to follow, as figures are apt to be, the chart show- 
ing the principal features of the copper industry from 
1913 through 1921 may help the reader to visualize 
how and where copper is used. 

The cost of copper, both from the point of view of 
the producer and the consumer, is important because it 
has much to do with how much is produced, consumed, 
bought, and sold. Jt will be found that the price of 
copper has fluctuated with that of other staple com- 
modities. During the war prices naturally rose when 


FROM EARTH TO INGOTS 141 


the demand was great, but since they have fallen as low 
as pre-war levels or lower. During the period of 
America’s participation in the war, copper had its 
price fixed by the Government, and it devoted itself 
almost exclusively to winning the war. Electrolytic 


IN CENTS 


PRICE 


POUNDS 


OF 
MILUONS OF POUNDS 


MILLIONS 


1913 1914 1915 1916 1917 1918 1919 1920 1921 
From ‘‘Mineral Resources, 1921’’ 


CHART SHOWING THE PRINCIPAL FEATURES OF THE COPPER 
INDUSTRY, 1913-21 


copper now sets the price pace for all other grades. 
As late as 1915 Lake copper sold at a premium of 
about one quarter of a cent over electrolytic due to 
an old belief in its superiority that originated in the 
days before the extensive production of electrolytic 
copper. Though Lake and electrolytic copper can 


142 THE STORY OF COPPER 


hardly be told apart, the tables have since been turned, 
with a slight premium on the electrolytic variety at 
times. 

When the United States Geological Survey made its 
superpower survey to determine the feasibility of a 
gigantic electrical system that would supply the whole 
of the North Atlantic section of the country. with elec- 
tric power generated at the coal mines and water- 
falls, it was naturally interested in the cost of copper, 
as the metal would be used in all of the electrical trans- 
mission systems, machinery, and wiring of this un- 
dertaking. An investigation of the cost of produc- 
tion of copper was made in order to obtain informa- 
tion for this project. It was found that during the 
period 1909-20 the average cost by the pound was 
11.35 cents. This figure did not include a charge for 
the depletion of the ore, which would range from two 
to four cents, or for the Federal income and excess- 
profits taxes that were very high during that period. 
The figures do include the mining, milling, smelting, 
refining, transportation, and selling costs, general de- 
preciation of plant and equipment charges, and all 
taxes except those noted. This investigation showed 
that it cost about four cents more to the pound to pro- 
duce copper from the native copper ore in Michigan 
than it does to obtain it from the vein mines, such as 
Butte and the disseminated-ore mines such as are 
found in Arizona and Utah. In 1920 the average cost 
of copper produced in all three types of mines was 
14.94 cents, while for the different types it was: vein 
mines, 14.2 cents; Lake mines, 18.2 cents; disseminated- 


FROM EARTH TO INGOTS 143 


ore mines, 14.6 cents. In 1920 the average selling 
price of copper by the pound was 18.4 cents. 

Such is the story of the way in which man coaxes 
copper out of its ore and makes it ready to play the 
part that belongs to it in the work in the world. 


CHAPTER VI 
COPPER’S INSIDE STORY 


Metals, like unfamiliar animals, and people of an- 
other race, look very much alike until they are known 
intimately. It is only after the acquaintance has 
ripened into recognition of their good and bad prop- 
erties that the peculiar qualities of each metal can be 
utilized to the greatest extent. 

Copper’s inside personal story is being revealed by 
metallurgist, engineer, and chemist; their science and 
skill have penetrated into many of the complexes of 
copper; but the innermost depths of the red metal 
have not been probed any more successfully than the 
precise workings of the human mind. Enough is 
known, however, to explain much of the metallurgy by 
rote that arose through copper’s long service to man. 
The examinations to which copper is subjected can 
show whether a particular piece is fit to undertake a 
given task and what treatment can be given it to put 
it in shape for a specified use. Metals are examined 
much more closely than ordinary, law-abiding citizens. 
They are photographed, given a certain treatment, 
and photographed again to see what happened. They 
are pulled apart, mashed, pounded, shocked with cur- 
rent, X-rayed, heated, and frozen. Their intimate 
composition, genealogy, and impurities are investi- 


gated. In fact, they are handled much more rigor- 
144 


COPPER’S INSIDE STORY 145 


ously than many people who have not kept within the 
law, and more is known about metals than about most 
criminals. 

First, let us assemble the fundamental data on cop- 
per and compare them briefly with that of other 
metals. With copper’s record before us we shall be 
able to discuss some of the explanations for its be- 
havior that have been offered by metallurgical detec- 
tives. The record sheets will come from three labo- 
ratories: the physical laboratory where mechanical 
tests are made, the chemical laboratory where the 
chemist takes the never-pure métal apart element by 
element to discover its composition, and the photomi- 
crographic laboratory where the interior structure of 
the metal is treated and photographed. 

The mechanical engineers and metallographers in 
the physical laboratory look copper over, note its gen- 
eral appearance, its reflexes, and take its Bertillon 
measurements, as it were. It is comparatively simple 
to determine copper’s inherent qualities, such as its 
color, weight, melting-point, expansion, and conduc- 
tivity, because they are not affected markedly by the 
way in which the copper is treated. But strength, 
hardness, ductility, and fatigue are harder to put 
down on paper because not only do they vary widely 
with the treatment of the metal, but they are hard 
to measure. Copper’s physical record reads some- 
what like this: Name—Copper, often abbreviated to 
Cu. Color—Peculiar red, which is pinkish or yellow- 
ish on the fresh fracture of the pure metal, slightly 
purplish if it has much cuprous oxide. Weight 
—For electrolytic copper, rolled, 558 pounds per cubic 


146 THE STORY OF COPPER 


foot, or 8.89 times the weight of water. This varies 
somewhat according to the purity and condition of the 
copper; cast copper, somewhat porous, may be as low 
as 8.2. Melting-point—1083 degrees Centigrade equiv- 
alent to 1981 degrees Fahrenheit. Electrical conduc- 
tivity—Copper is usually taken as the standard for 
conductivity comparisons, and called 100. The inter- 
national standard value for the electrical resistivity of 
annealed copper is 0.17241 ohm for a column of cop- 
per a meter long and a square millimeter in cross- 
section. Linear expansion—For each degree increase 
in its temperature, Centigrade, copper will expand 
0.00001678 of its own length. Thermal conductivity 
—0.918 small calorie of heat will be transmitted 
through one square centimeter of a plate of copper 
one centimeter thick in one second when the difference 
in temperature between the two sides is one degree 
Centigrade. Such is a portion of the record of copper 
under ordinary conditions. Some parts of it even in 
the reduced form in which it is presented probably 
seem unnecessarily complex, but such information in 
great detail is valued by those who study copper and 
predict what it can do. The other and more variable 
physical properties are somewhat as follows: Tensile 
strength—Varies with the condition and purity of the 
copper from about 22,000 to 67,000 pounds to the 
square inch. Typical values for various kinds of 
copper are: Cast, 25,000; soft and annealed at 200 
degrees C., 38,000; hard drawn thin wire or hard rolled 
thin plate, 67,000. Compressive strength—Copper of 
good quality does not fail in the compression test by 


COPPER’S INSIDE STORY 147 


fracture; it merely yields indefinitely and becomes flat- 
ened out. Hardness—This property is expressed in 
many ways. On the Mohs mineral scale of hardness, 
copper has a hardness of 2.5 to 3, between that of the 
crystallized minerals gypsum and calcite. The two 
methods of testing hardness in the physical laboratory 
are by the scleroscope, on which annealed copper varies 
from 6 to 7, and hard copper varies from 22 to 24, and 
the Brinell ball test, by which the hardness of annealed 
or cast copper is about 35 and hard copper may regis- 
ter as high as 100. Elongation—When the test speci- 
men of copper is stressed so as to pull apart, this 
tension causes an elongation of the metal before frac- 
ture occurs and, depending upon the kind of copper, 
this lengthening will be from 40 to 50 per cent. for an- 
nealed copper to only 1 or 2 per cent. for hard wire. 
In strength and hardness it is difficult to compare dif- 
ferent kinds of copper. The form in which they are 
tested, the kind of testing machine that is used, the 
treatment accorded the metal during test, and many 
other factors enter in to distort the result. As a con- 
sequence, national societies, particularly the American 
Society for Testing Materials, and the Government 
have prepared specifications for copper for various 
uses, which provide how the metal shall be sampled 
and tested, mechanically and physically. 

Although comparison of other metals with copper 
is even more vague and inadvisable than the contrast- 
ing of different kinds of copper, a greatly condensed 
list of physical properties of the common metals, in- 
cluding copper, is given. It will probably allow you 


148 THE STORY OF COPPER 


to form an opinion as to the rank of copper in the 
world of metals. Do not be afraid to read it just be- 
cause it is a table of figures. 


Metal Chemical Atomic Density Weight Melting Electrical Heat 

Symbol Weight Ibs. per _ point Conductivity Con- 

cu. ft. Degrees (Copper 100) duc- 
Centigrade tivity 
Copper Cu 63.57 8.89 558 1083 100 . 918 
Aluminum Al PA ie 2.57 160.5 658.7 60.5 48.0 
Gold Au 197.2 19.3 1203 1063.0 71.8 70.5 
Iron Fe 55.84 7.8 487 1530 17.4 16.1 
Lead Pb 207.20 11.38 710 327 7.8 8.3 
Magnesium Mg 24.32 ttf 106 651 35.8 37.6 
Nickel Ni 58.68 8.3 518 1452 22.0 14.2 
Platinum Pt 195.2 21.5 1342 1755 age, 16.6 
Silver Ag 107.88 10.5 655 960.5 106.2 100.6 
Tin Sn 118.7 7.3 456 232 12.0 15.5 
Zine Zn 65.37 7.0 437 419.4 rae 26.5 


Chemical symbols are simply the nicknames or ini- 
tials with which the scientist has dubbed the elements. 
They also stand for one atom of the element and all 
its properties. Atomic weight tells how many times 
heavier than hydrogen gas an element is when it is in 
its gaseous state. The figure for density tells the 
number of times the metal is heavier than water. As 
copper is surpassed only by silver as an electrical con- 
ductor, electrical conductivity is often expressed as a 
comparison with that of copper. The figure under 
‘‘Heat Conductivity’? allows a comparison of the 
amount of heat that metals will allow to pass through 
them. Note the close relation to electrical conductiv- 
ity. The figure is the number of hundredths of small 
calories of heat transmitted per second through a 
plate one centimeter thick, per square centimeter of 
its surface when the difference of temperature he- 
tween the two sides of the plate is one degree Centi- 


grade. 


COPPER’S INSIDE STORY 149 


The tensile strength of the pure metals is not so 
important as that of some of their combinations with 
other metals or impurities. By glancing over the fig- 
ures below expressed in pounds per square inch ten- 
sile strength and comparing them with the figures for 
copper previously given, an idea of copper’s place in 
metallic strength will be obtained. Brass, cast, 
29,000 to 46,000, hard rolled, 55,000 to 75,000; bronze, 
7000 to 48,000; iron, pure, 55,000, cast, 35,000 to 57,000, 
wrought, 48,000 to 53,000; carbon steel, 46,000 to 
175,000; alloy steels, 75,000 to 330,000; aluminum, 
east, 12,000 to 14,000, hard wire, 40,000; gold, 25,000 
to 37,000; lead, 1780 to 3300; magnesium, 30,000 to 
33,000; nickel, 38,000 to 150,000; platinum, 35,000 to 
03,000; silver, 40,000 to 51,200; tin 4000 to 10,000; 
zine, 4000 to 36,000. Tungsten wire has been pro- 
duced with a strength of 450,000 pounds to the square 
inch. 

A method of analysis that has netted important 
results in better and cheaper metal and manufactur- 
ing practice involves polishing, etching, and then 
photographing the copper specimen through the micro- 
scope. Chemical analysis, despite the inroads made 
by the younger optical method, is extremely useful 
and necessary in examining copper from the time that 
it is mined until it is used. At virtually every stage 
of copper’s journey to work, exactly how much copper 
there is in the material must be known. The chemist 
gives this information. Many reagents are used; to 
the chemicals themselves are added electricity and 
fire, and the chemist must be able to identify and ac- 
curately determine the quantity of all the impurities 


150 THE STORY OF COPPER 


that copper may acquire, intentionally or unintention- 
ally. Fire assaying of copper containing ore, and the 
determination of lead, silver, gold, and platinum as 
well, is practised, and refined copper is often assayed 
electrolytically. Comparatively recently it has been 
realized that the gaseous as well as the solid constitu- 
ents of copper must be found and listed in an analysis. 
Hydrogen and sulphur dioxide dissolve in copper 
and will be reported in analyses of the future. Non- 
chemical methods are being perfected to replace 
tedious titrations and filtrations, or, what is more 
often the case, to determine quantities of impurities 
in copper too small for the ordinary methods of the 
chemist to detect. When a flaming are of copper is 
viewed with the spectroscope, it is found that each 
element has its own exclusive bands of lines that ap- 
pear only when that element is there. The spectral 
lines also vary in brightness with the quantity of their 
metal that is present, and this difference in bright- 
ness is especially easy to determine when quantities 
less than a very small percentage are present, the area 
where quantitative chemical methods are often weak- 
est. A few hundredths of a gram of material will 
usually suffice for spectographic analysis and with the 
spectograph impurities will be recognized that would 
require many hours of chemical work to detect. The 
faint presence of harmful antimony in lake coppers is 
quickly proved by the spectrum, and whether low con- 
ductivity in copper is due to arsenic, nickel, or some- 
thing else may be quickly found out. Slight traces of 
such deoxidizers as boron, magnesium, manganese, sili- 
con, and vanadium may be identified when chemical 


COPPER’S INSIDE STORY 151 


analysis will fail to detect them even though days of 
effort are spent. As complex alloys of any kind are 
dissociated by heat into a spectrum that contains the 
tell-tale lines of each metal present, the secrets of 
the inventors of alloys and hardened metals are no 
longer hard to unravel. The spectrographic method 
is speedy and self-recording. In fact, the spectrum 
ean be photographed by an assistant in the laboratory, 
deciphered by an expert at his leisure, and filed away 
for permanent record or future use. 

The microscopist is the scientist who actually looks 
into the metal and sees how it is put together. The 
physical tester judges the metal by its qualities in a 
large piece, the chemist disintegrates the metal to in- 
vestigate, but the user of micrometallurgical methods 
polishes and etches a specimen and then uses his mi- 
croscope and his eyes or his camera. For the micro- 
metallographic sleuth no trail is too cold, provided 
his metallic clue or sample has been untampered with 
and is unchanged. From an inspection of the sample 
he can often tell the past history of the metal’s treat- 
ment and the reason for its excellent or poor qualities. 
Before an enlarged view of the metal is taken, a piece 
of the metal is looked at to determine whether the un- 
glassed eye can detect any features. The eye is aided 
by employing an etching solution, such as ammonium 
persulphate, to reveal the macrostructure; although 
usually the relative size and arrangement of crystals, 
the features most often shown by unmagnified ob- 
servation, do not need to be etched. The first step 
toward an examination under the microscope is the 
selection and grinding of the specimen. During the 


152 THE STORY OF COPPER 


cutting and polishing, it is usually important that the 
edges be left in their original condition, and copper is 
used to protect them. A layer of copper is electro- 
lytically deposited on the specimen. If the specimen is 
of copper itself, a very thin film of nickel is deposited 
first so as to divide the original copper from the pro- 
tecting layer. A rough grinding is followed by grind- 
ing with a finer abrasive; polishing that concludes with 
the use of impalpable alumina, grit-free, applied with 
very fine cloth, leaves the surface very smooth and 
ready for examination. Though some metals are ex- 
amined unetched, usually a solution must be applied 
that will slightly dissolve some component of the 
metal and leave the remainder standing in high relief. 
For copper and copper-rich alloys, various etching re- 
agents are used. Oxidation, the same process that 
takes place at some other places in copper’s career, 1s 
of fundamental importance in successful etching of 
copper-containing metal. Many reagents that ordi- 
narily have only a very slight solvent action upon cop- 
per and copper alloys may be successfully used for 
etching if oxidizers are added or oxygen gas is passed 
through the etching reagent while the specimen is im- 
mersed. With an ammoniacal or an acid solution the ~ 
following oxidizers can be used as etching solutions: 
hydrogen peroxide, ammonium persulphate, potas- 
sium permanganate, potassium dichromate, chromic 
acid, ferric chloride. An etching reagent consisting 
of an ammoniacal solution of copper-ammonium 
chloride is electrolytic in its nature, and nitrie and 
chromic acids, oxidizing in their nature, can be used. 
If oxidizers are used with concentrated ammonium 


Cc it 


Courtesy of National Bureau of Standards 


PHOTOMICROGRAPHS OF COPPER’S DIFFERENT APPEARANCES 


The crystal structure of cathode copper just after electrolysis is shown in “a.” 
The etched cross section of copper depcsited on an electrotype, ‘‘b,’’ shows off the 
tall crystals to better advantage. ‘‘C’’ is cast copper, and the dark intrusions are 
cuprous oxide. The elongated crystals in ‘‘d’”’ show that this is a specimen of hard 
drawn cold copper wire, and ‘‘e’’ is the appearance of soft wire whose crystals 
have been relieved of the strain of drawing; ‘“f’? shows what the structure of a 


quarter inch hot rolled copper plate looks like. Magnification of “a,” “b,’”’ ‘“c’” and “f’ 
is 100 times, of “d” and “‘e,” 250 times. 


Photograph by Dr. R. W. G. Wyckoff, Geophysical Laboratory, Carnegie Institution of Washington 


ATOM PLANES OF COPPER SULPHATE 


The actual atoms of the crystal of copper sulphate are responsible for the 
symmetrical pattern of the crystal lattice shown in this photograph, for the wave- 
lengths of the X-rays which took the picture are small enough to be reflected by 
those infinitesimal particles. Laue, a German scientist, in 1912 first proved, by 
means of a copper sulphate crystal, that X-rays could be used to photograph the 
crystal atom planes. A year or so later, W. L. and W. H. Bragg, in England, 
measured the distance between the atoms by making such photographs as this 
from different viewpoints, and then used a measured crystal to determine the wave- 
lengths of X-rays. The magnitudes with which such measurements deal are in 
the neighborhood of a billionth of an inch, or about one thousandth of the wave- 
length of light. 


COPPER’S INSIDE STORY 153 


hydroxide, it will give satisfactory results in etching. 
‘‘Heat tinting,’’ which consists of oxidizing unequally 
the different components, is valuable for certain 
bronzes. 

Under the microscope, pieces of copper look so un- 
like that it is hard to realize that they consist of the 
same element. Slight impurities or differences of 
treatment remake the whole metallic landscape. The 
purest copper produced commercially, that which has 
been electro-deposited and not remelted, or has been 
remelted in a vacuum, consists of an aggregate of cop- 
per grains or crystals. When these crystals are pres- 
ent in the coating of copper on an electrotype, they 
show their twinning and their column structure to 
much better advantage. What a great difference five 
hundredths of 1 per cent. of copper oxide makes in 
copper’s structure! In a piece of cast copper, the 
fallen forests of crystals have turned to a plane of 
copper with circular markings of copper oxide. This 
is the small amount of oxide that is left in the metal 
after it has been poled during fire refining. The cu- 
prous oxide does not dissolve in the solid copper, and 
under the microscope its bluish-gray color with a red 
glow at the center of every particle differentiates it 
from any other inclusion in copper. It is even pos- 
sible to use an area-measuring device on a photomicro- 
eraph and determine the amount of oxide present. 
The structure of cast copper is broken up by the heat- 
ing, rolling, and drawing that it undergoes in the mill, 
the oxide is distributed through the copper in smaller 
pieces, and the structure takes on the appearance. of 
the photographs showing hard drawn wire, soft wire, 


154 THE STORY OF COPPER 


and hot rolled sheet. When copper is drawn into 
wire and made hard by the process, the oxide forms 
itself into rows of fine globules, parallel to the direc- 
tion in which the metal is worked, and the grains 
elongate in the same direction. When the wire is 
softened by annealing, the copper crystals seem re- 
lieved to be free from their strain and arrange them- 
selves in an easier position. The grains of copper 
are very small; their diameters are from 0.0005 to 
0.015 inch. Bismuth and lead, which show themselves 
as small particles, are other impurities that can 
be detected by micrographic methods, but other for 
eign material cannot be found by this method. The 
search for silver, gold, nickel, manganese, arsenic, an- 
timony, zinc, phosphorous, and other impurities is 
left to the chemist. 

The reasons for copper’s pleasant properties and 
the formation of its microscopic landscapes of crystals, 
like the causes of the structure of the other metals, 
are major questions that scientists are attempting to 
answer to-day. Probably the most curious phenome- 
non of all nature is the way almost all the atoms in 
the world insist upon arranging themselves in or- 
derly positions. Whenever they find themselves free 
to move, aS when they make up a gas or are in a 
liquid, either a solution or a molten substance, the 
atoms rush about with a good deal of energy, but 
as soon as they, from cooling or other cause, find their 
range of activity decreasing, they face about and get 
in line with other atoms, the lines form squads, the 
squads platoons, and soon a crystal is built up. It 
is possible, by controlling conditions very carefully, to 


COPPER’S INSIDE STORY 155 


build up the whole number of atoms into one very 
large crystal, but ordinarily there is too much hurry 
and confusion for this to happen. Crystallization 
starts usually in many places throughout the liquid 
at the same time. The near-by atoms hasten to join 
with those whose ranks are closing up, and the erystals 
grow. But before they have grown very large they 
begin to interfere with each other. They actually push 
against each other, and many different things may 
happen. One striking result of the struggle is twin- 
ning, when two crystals headed in opposite directions 
grow through each other. Often the crystals are 
squeezed into other forms than the one they are try- 
ing to assume, and queer,.misshapen forms occur. 
This is especially likely to happen when from a mix 
ture of two substances one begins to crystallize a little 
before the other. The crystals already formed resist 
the growth of the new crystals to such an extent that 
the second kind often have to slip in between, form- 
ing long chains of tiny crystals called ‘‘dendrites”’ 
because they grow in much the same way as moss be- 
tween rocks. In a homogeneous material, the large 
erystals usually stop growing when they begin to in- 
terfere with each other, and the remaining atoms 
get together and build up smaller crystals in the chinks 
between them. There is no reason to suppose that this 
process should stop with crystals which we can see. 
In fact, smaller and smaller crystals have been found 
as more and more delicate means of detecting them 
have been invented until it is all but certain that the 
shape of the individual atom is a tiny replica of that 
of the perfect crystal. 


156 THE STORY OF COPPER 


Offhand, we should expect either that all crystals 
would have the same shape or that each would have its 
own characteristic shape. Broadly speaking, neither 
is true, although the trained crystallometrist can de- 
tect minute differences between crystals of one kind 
of matter and those of another. There are really just 
six types of crystals. Why there are so many—or so 
few—we do not know. Copper, like most metals, tends 
to arrange itself in cubes, or in double pyramids. As 
crystals are described, these forms are the same; each 
figure has three equal axes of symmetry at right angles 
to each other, running through the figure and connect- 
ing the opposite faces, or points, as the case may be. 
Another sort of crystal has only two of its axes at 
right angles to each other, while the third leans away 
from the vertical. This is called the monoclinic, ‘‘one 
inclined,’’ and is the system of several of copper’s' 
salts, especially the carbonates. Again, all three of 
the axes may make angles which are not right angles, 
and the crystal that results from this arrangement is 
called the triclinic. The best known example of a tri- 
clinine crystal is copper sulphate, blue vitriol, which 
forms such large, beautiful, glassy shapes. Not all 
crystals, however, stop at three axes. It is not neces- 
sary to have a four-dimensional figure to have four 
axes, for three of the lines are at right angles to the 
vertical axis and make with each other angles of thirty 
and sixty degrees. The resulting crystals are hex- 
agonal in shape. Copper does not use this system for 
its compounds. The remaining two systems are some- 
what like the first one, and it is a rather technical job 
to recognize them. Metals usually cool so fast that 


COPPER’S INSIDE STORY 157 


they have no time to do a good job at crystallizing, and 
perfect crystals in their structure are very rare. They 
form rather a mere frame or skeleton of their char- 
acteristic type. | 

The peculiar thing about the crystalline shape is 
that it seems that it cannot be destroyed. You may 
break a crystal, or even pound it to powder, but every 
breakage is along a cleavage plane so that the crystal 
only splits up into smaller crystals of the same type. 
It is readily seen that large single crystals have little 
strength to withstand rough treatment without injury. 
But a large number of small crystals growing together 
in such a way that their cleavage planes lie in every 
direction ought to give a much stronger mass. They 
do, and this is just what the metal-worker aims for. 
Since he cannot, to save his life, keep crystals from 
forming, he tries to keep those that do form reasonably 
small and well mixed up, or, as he says, he wants a 
fine-grained metal. The actual size of crystals formed 
in the different metals varies a great deal with the 
use to which the metal is to be put. No doubt you 
have noticed the mottled appearance of the surface of 
galvanized iron. This is caused by very large zinc 
crystals. And as there is no need for that zine coat- 
ing to exhibit tensile strength, hardness, ductility, or 
the other physical properties for which fineness of 
grain is necessary, it is perfectly practical to let the 
zinc crystals grow big. On the other hand, copper 
which is to be drawn out several thousand times its 
length into wires must be fine grained so that it will 
draw smoothly. 

Metallurgists are vitally concerned in the funda- 


158 THE STORY OF COPPER 


mental connection between crystalline form and the 
hardness of the metal. They know that working a 
metal makes it harder and that it also deforms the 
crystals, drawing them out in the direction of work- 
ing’ and squeezing and flattening them in the other 
direction. But the resistance of the crystals to this 
treatment and their tendency to return to their nor- 
mal shape make the worked metal brittle as well. 
Therefore most metals, after working, must be heated 
to some temperature below their melting-points and 
held there for a while until the crystals have recovered 
from their strenuous experience. This is annealing. 
It restores the metal’s malleability or ductility, but, 
unfortunately, softens it up again. A. nice balance 
must be worked out between the two extremes. Sir 
George T. Beilby, an English physicist, formulated a 
theory which accounts for the hardening of metals 
under deformation. According to his hypothesis, the 
working of the metal, which makes the crystals slide 
over each other along slip-planes, acts like a polish- 
ing process and causes very fine particles to rub 
off the crystals and collect around them. These par- 
ticles then flow together to form a sort of film around 
the crystals. Since the fine, amorphous material 
would have no crystalline slip-planes, it would be 
harder, for it would offer more resistance to deforma- 
tion. There are some metallurgists who object to this 
theory on the ground that the finest particles in the 
thinnest copper leaf can be proved to be erystalline, 
and it does not seem probable that the working of 
large sheets of the metal could produce a greater pro- 
portion of amorphous material than the drastic ham- 


COPPER’S INSIDE STORY 159 


mering which produced the leaf. Moreover, long ago 
it was found that electroplated copper three to five 
millionths of a millimeter thick has the properties 
of massive copper, and it is doubted whether cold work 
could produce fragments of this size. Again, others 
complain that if enough amorphous metal were pro- 
duced to account for the hardening, all the crystals 
would be used up in a bar of copper by the time it had 
been drawn to five hundred times its length, while it 
can in reality be drawn out without annealing to 
five thousand times its length and still be erystalline 
But, when Beilby’s hypothesis is modified somewhat 
by American metallurgists so as to be in accordance 
with the experimental facts, no better theory has been 
put forth to explain strain hardening. There is, how- 
ever, still a great chance and much need for brilliant 
fundamental scientific work on the structure of metals. 

Walter Rosenhain, the English metallurgist, has 
suggested, also, that a film or thin layer of amorphous 
metal exists around each crystal of metal, even when 
it is totally unstrained and in its natural state. This 
‘‘inter-crystalline amorphous cement’’ theory has 
good experimental backing in the fact that when a 
piece of metal is pulled apart the breaks will occur 
through the crystals themselves and not at the boun- 
daries between crystals. While some of this is theory, 
it rests on a firm foundation of facts about the very 
interior of metals. 

With his recently developed sixth sense man has 
been able to probe into the very depths of metals and 
learn their structure. The X-rays, shorter and more 
powerful than the light-rays that we see, have made 


160 THE STORY OF COPPER 


known the arrangement of atoms in the metallic 
crystals with the same clarity with which they show 
the framework of the homan body. When Laue found 
in 1912 that X-rays of uniform frequency or wave- 
length projected into a mass of fine crystals would be 
reflected in an orderly manner by regularly spaced 
atoms of crystals, he gave the metallurgist a new tool 
and he opened what had been a closed door into the 
interior of metals. W. L. and W. H. Bragg developed 
the X-ray spectrometer based on Laue’s work, and 
the possibilities of this instrument in metallurgiéal 
work are scarcely realized even now. It has revolu- 
tionized our ideas on the constitution of solids. 

The highest power microscope is feeble compared 
with the X-ray spectrometer. If two lines are sepa- 
rated by one thousand times the distance between two 
neighbor atoms in solid copper, these two lines would 
appear as one through the best microscope that the 
world knows. The microscope cannot hope to do any 
better, because it is limited by the wave-length of 
light. But with the X-ray wave-lengths of only one 
fourth the distance between two atom rows, man may 
peer into the crystals of metals, not with his eyes, but 
by using the sensitive photographic plate. The X-rays 
reflected will impress on the negative a series of lines 
or bands whose spacing will depend upon the geom- 
etry of the internal structure of the crystal and 
tell just how the atoms are arranged. Thus, with this 
most modern sense, we are able to ‘‘see”’ into metal 
and actually think in terms of the positions of the 
atoms in crystals. 

The X-ray shows that atoms of copper form in the 


COPPER’S INSIDE STORY 161 


same shape as the copper crystals that are seen under 
the microscope. The copper crystal is a cube with an 
atom at each corner and an atom centered in the sur- 
face of each face. Hach side of this cube is just 3.60 
Angstrom units long, which in every-day extraordi- 
nary language is fourteen ten-millionths of an inch. 

Having located the metallic atom, the metallurgist 
ean find out more about it and its effects on visible 
metal, and he is proceeding to do so. At present it 
is said that only two X-ray spectrometers, one in 
England and one in America, are being used for 
metallographic research. These will undoubtedly mul- 
tiply many times. 

Very closely linked with the hardness of copper 
is its most important property, its ductility. Ductil- 
ity is very difficult to measure satisfactorily, so that 
it is impossible to give figures comparing copper with 
other metals in this important respect. But it 1s cop- 
per’s ductility that allows it to be drawn out into the 
fine wires that have made possible the enormous de- 
velopment of electricity. The ability to be rolled out 
into thin sheets is also included under the term, and 
the word ‘‘working’’ is used in practice to cover both 
rolling and drawing. When copper is worked its ten- 
sile strength and hardness are increased. Those who 
hold to the amorphous metal theory explain this change 
in properties as due to the formation of amorphous 
material, and indeed the grain of worked copper is 
finer than before the deformations took place. This 
working and change of grain size leaves the metal with 
a tendency for the crystals to resume their normal size 
and shape, and this is what is called a strain in the 


162 THE STORY OF COPPER 


strueture. It makes the metal brittle and, under some 
conditions, may crack it. Hard-drawn trolley-wires 
usually get no further treatment after being drawn 
to their required gage, but most copper products are 
annealed after receiving their final shape to get rid of 
these strains in them. Heated to a temperature which 
will allow recrystallization without deforming the 
piece, the original alinement of the atoms is, at least 
to some extent, restored, the crystals grow, and the 
imposed hardness disappears. 

The hardness of copper wire when it is drawn has 
some effect on the electrical conductivity, for it is 
found to be a poorer conductor than soft annealed 
wire by nearly 3 per cent. This is not a great deal, 
and the impurities which occur with copper and are 
not removed by refining affect the conductivity to a 
much greater extent. Especially prominent among 
these is the cuprous oxide which contact with the air 
always forms to some degree in copper that has been 
melted. This compound of oxygen and copper im- 
pairs both the conductivity and the ductility of cop- 
per; nevertheless it does not pay to reduce the copper 
until less than 5 per cent. cuprous oxide exists in it, 
for the other metals, such as lead, arsenic, iron, nickel, 
and aluminum, which make up the rest of the impurities 
in commercial copper would also be reduced from their 
oxides to the metallic form, and they are much less 
harmful when they remain as oxides. The conductiv- 
ity of copper is decreased 3 per cent. when 0.01 per 
cent. metallic arsenic is present, 24 per cent. when 0.1 
per cent. is present, and 38 per cent. when 0.2 per cent. 
is present. The matter is compromised by getting the 


COPPER’S INSIDE STORY 163 


greatest possible proportion of pure copper without 
bringing in any extra disadvantages. Although these 
other metals are harmful so far as conductivity is con- 
cerned, they may prove quite beneficial for copper used 
other than electrically. Arsenic, for instance, helps 
copper carry on when it finds itself obliged to work in 
very hot places where there are harmful gases, as 
in stays for the fire-box of a locomotive. 

The cuprous oxide that is always present in ordinary 
copper makes no trouble as a general rule, but it must 
be watched for two reasons. If copper is annealed at 
too high a temperature, too much oxide forms, and 
the copper is, literally, ‘‘burnt.’’ This not only makes 
it brittle, but forms a starting-place for corrosion to 
eat in between the crystals where the particles of oxide 
lodge. Not only ‘‘burning,’’ but ‘‘gassing’’ 1s an ac- 
- cident whose results to copper are likely to be fatal. 
The ‘‘gas’’ is steam formed within the grain of the 
metal, and this is the way it happens. Heating may 
take place in either an oxidizing or a reducing manner. 
If copper is heated in such a way that plenty of air 
ean reach the hot surface, it will combine with the 
oxygen in the air to form its oxide. But if the amount 
of air is limited or if the air which is present cannot 
eet to the copper because a flame is played closely over 
the surface, oxygen already in the copper as oxide 
feeds the flame and the oxide is reduced to metallic 
copper. Strangely enough, one of the products of 
flame is water, and so under these circumstances steam 
is formed. This would not make much difference if 
the metal being heated were liquid, for the steam 
could bubble up through it and escape, but to get out 


164 THE STORY OF COPPER 


from the solid copper it has to use its explosive vio- 
lence which, of course, cracks the metal. This failure 
is sometimes produced during brazing of copper or its 
alloys, if the metal is not manipulated properly while 
heating. 

The most frequent ‘‘discovery’’ made in copper 
metallurgy is that of the ‘‘lost art’’ of hardening cop- 
per. Often thrilling accounts of a new process that 
will revolutionize the copper business find their way 
into the press; periodically patents are applied for 
in the belief that the ‘‘mysterious’’ method of ‘‘tem- 
pering’’ copper supposedly evolved by the ancients 
has been refound. Of course there is nothing new or 
mysterious in hardened copper. Immense quantities 
are in use and more is being added daily. There are 
two well-known methods of hardening copper. As in 
the case of hard drawn copper trolley-wires and cold 
drawn copper tubing, rolling and drawing can produce 
a harder metal because of crystal rearrangement. 
Hammering has the same effect. The other common 
hardening method is that of alloying. Directions that 
are given in the ambitious but unscientific patents 
remind one of the metal-working formule of the al- 
chemists of the middle ages. For instance: ‘‘Heat 
the copper to 260 degrees to 315 degrees and subject it 
while hot to fumes of burnt sugar and animal fat at a 
temperature below that necessary to form carbon mon- 
oxide.’ | 

Many times those who try to regain the lost art of — 
hardening copper unconsciously use the common 
method of alloying: The metal is remelted and the 
process so manipulated that the copper becomes satu- 


COPPER’S INSIDE STORY 165 


rated with cuprous oxide; the product is much harder 
and more brittle than pure copper. Cuprous oxide 
alloys with copper in exactly the same sense that 
metals do, and hence this process is only a variation of 
‘‘hardening’’ by alloying. The fact is that there never 
was known to ancient men any art of mysterious cop- 
per hardening to be lost. The late Professor William 
Gowland of the Royal School of Mines, an authority 
on copper in antiquity, destroys this prevalent myth 
in the following words: 

‘*The castings of knives, swords, etc., generally were 
hammered at their cutting edges, and it is to this 
hammering, and to it only, that the increased hardness 
of the cutting edges of both copper and bronze weapons 
is due, and not to any method of tempering. Much 
has been written about the so-called art of tempering 
bronze, supposed to have been practised by the men 
of the Bronze Age in the manufacture of their 
weapons; the hardness is also said to be greater than 
can be given to bronze of the present day. I should 
like to correct this error, as it can only have arisen 
owing to its authors never having made any compara- 
tive practical tests of the hardness of bronze. Had 
they done so, they would have found that the ordinary 
bronze of to-day can be made as hard as any, in fact 
harder than most, of prehistoric times, by simple ham- 
mering alone.’’ 

Copper has nine big assets in life. They are: its 
electrical conductivity, its capacity for conducting 
heat, its extreme ductility, its malleability, its high 
tenacity, its ability to alloy with other metals, its 
high serap value, its artistic color and luster, and its 


166 THE STORY OF COPPER 


quality of withstanding corrosion. Its current-carry- 
ing capacity serves it principally when it is employed 
in the electrical field; its superior working qualities 
stand it in good stead when it is being prepared 
for the world. Its other qualities are not always 
important, but its hardiness in the face of the ac- 
quisitive elements is a point in its favor no matter 
where it is or how it is used. Red copper, uncom- 
bined, is naturally an unfriendly substance. In dry 
air the amount of the attack by oxygen is insignificant, 
and this is also true if moist air is free from much 
carbon dioxide, the gas that we manufacture and ex- 
hale from our lungs. If air is not present, dilute 
hydrochlorie and sulphuric acids do not dissolve cop- 
per, though it is dissolved by nitric acid and by hot 
concentrated sulphuric acid. In the presence of air 
dilute acids attack it very slowly. But hot and cold 
water flow over copper year after year and leave it 
just as they found it. 

If the conditions to which a substance 1s exposed do 
corrode it, the logical thing to do is to separate the 
material from its attacker. Iron rusts, forming an 
ugly red surface; therefore coats of paint are applied 
continually to keep the moist air away from uncor- 
rodediron. The layer of iron oxide or rust that forms 
if paint is not used does not have the property of pre- 
venting further inroads of corroding material, but 
rather aids more air and water to get to the iron. 
On the contrary, copper, like the human skin that has 
been sunburnt, creates out of itself protection against 
the few natural combinations that tend to corrode it. 
And the coat of green carbonate, unlike iron oxide, 


COPPER’S INSIDE STORY 167 


prevents the further disintegration of the metal and 
is more becoming to the average roof than a heavy 
coat of tan is to the average person. Copper patina 
costs much less than many coats of paint for iron or 
a trip to the sea-shore to acquire sunburn; the ex- 
pense of copper’s protection is included in the first and 
only price of a copper sheet, and there is no further 
charge as time goes on. Largely because of copper’s 
superior ability to stick to its metallic state and the 
consequent lack of complaints as to its conduct, few 
extensive investigations have been made on its rela- 
tive corrosion. In one case, however, copper was ex: 
posed to corrosion in competition with aluminum, iron, 
and steel with a victorious result. The observed rates 
of corrosion expressed as the decrease of thickness per 
year in fractions of an inch were: 


On Office Building In Railway In Smoke- 


oof Tunnel stack 
Copper (plain) ..... 0.0000 0.004. 0.014 
Ue ESS a a 0011 013 trite 
POU Piette ela ck os 0.001—0.004 15 .018 
SES) La a OR a he .020 


Copper thus protects itself well against aggression 
and in one case it has the ability of transferring a 
little of its immunity to another metal. When a little 
copper (about a quarter of 1 per cent.) is added to 
steels they are made more resistant to rusting when 
exposed to the atmosphere. This protection does not 
apply to the copper-bearing steels when they are im- 
mersed in liquids, and it is yet to be discovered just 
how copper prevents atmospheric corrosion. 

A look into copper’s personal history shows that it 
has many qualities to make it worthy of the reliance 


168 THE STORY OF COPPER 


and dependence that man places in red metal. Ever- 
lastingly on the job, it sticks to its freedom and un- 
der nearly all conditions has the ability of finishing 
the work assigned to it. It stands a large amount of 
hammering and much pulling; it only becomes harder 
when ‘‘treated rough.’’ Coupled with its ease of work- 
ing is a tenacity of purpose that is seldom surpassed 
among the metals. If it becomes embrittled through 
punishment, a little heating and slow cooling will re- 
store it to tranquillity and an annealed state. As a 
carrier of impulses and power of an electrifying nature 
without loss in transit it is surpassed by only one 
metal, silver, which is too high-priced to be of much 
practical service. And copper is a good mixer. Use- 
ful as it is alone, it shows even greater ability when 
aided to a small extent by some other metal. But that 
is a story all to itself. 


CHAPTER VII 
COPPER’S CHEMISTRY 


From a chemical point of view, copper is one of 
the bricks of which the universe is built. There are 
some ninety-two kinds of these elements, if we include 
several which are known to exist but are still undis- 
covered, and some or all of them make up not our 
own earth alone but every star as well. In order to 
realize the interesting place which copper holds among 
these elements, we must take the universe apart and 
see how it is made. 

Let us take our earth as a chemist’s tiny sample of 
the universe and give it what he would call an ulti- 
mate analysis. Into an imaginary furnace we shall 
place the whole of it: houses and lands; trees, animals, 
and people; mines and factories; oceans and the at- 
mosphere that surrounds our globe. The chemist’s 
furnace has various devices hitched to one end of it 
which sort out and imprison the few elements of which 
he knows his sample is composed. To our gigantic 
furnace let us imagine some such attachment that will 
separate element after element as they come out. 
Our interest in observing nearly everything hes in 
its resemblance to other objects or its difference from 
them. As we watch the elements issue from the exit 


pipe of our furnace and line themselves up in order 
169 


170 THE STORY OF COPPER 


we are struck with the great variety of appearances 
which our ‘‘bricks’’ present. 

The most familiar in appearance are the metals, 
which make up more than two thirds of the whole 
exhibit. Some of them we recognize at once. Our 
familiar copper, iron, nickel, zinc, tin, aluminum, gold, 
silver, mercury, lead, and platinum are allhere. There 
are many more that we have never seen before. All 
have the characteristic shiny ‘‘metallic’’ look. Most 
of them have the same color, or lack of color. Silver 
and platinum, zine and lead, tin and nickel, all look 
very much alike. We are accustomed to think of that 
gray as the color of metals, with copper and gold as 
shining exceptions. Now we see other reddish and 
yellowish metals among the lot. Manganese and bis- 
muth have the red tint, while neodymium, presody- 
mium, and cesium are yellow. Mercury is the only 
metal that occurs as a liquid. 

The remaining third of the elements present every 
variety of appearance. Ten are gases. Of the divi- 
sion cf non-metals also one, namely bromine, is a 
liquid. 

As this company of between eighty and ninety in- 
dividuals draws up before us, the questions almost in- 
evitably arise: Why this great number and variety 
of substances? How did they all come to be? 

If we now bring in a set of chemical reagents and 
put the elements through their paces, we may again 
compare them. Some of them are not affected in the 
least.’ Suppose we group these together and set them 
to one side. All are gases. We meet them every day, 
for they are a part of the air that we breathe, but 


COPPER’S CHEMISTRY 171 


they are as invisible as they are chemically inert. The 
first and lightest of the group is helium, which is 
sometimes used in the gas-bags of dirigible air-ships. 
It is named for the sun, where it was first discovered. 
The next one is neon, whose name means ‘‘new,’’ ar- 
gon, the ‘‘lazy,’’ follows; then krypton, the ‘‘hidden’’; 
and xenon, the ‘‘stranger.’’ The last known member 
is niton, a descendant of radium. Its characteristics 
differ somewhat from those of the other elements of 
this group as one would expect of a member of the 
erratic radio-active family. Although the above ele- 
ments are so uninteresting in their chemical behavior, 
they play a considerable part in answering our ques-’ 
tions as to how the elements come.to be. We shall meet 
them later. 

In experimenting with the remaining elements, which 
are the chemically active ones, we find the metals and 
the non-metals taking sides against each other. Let 
them but find themselves suitably disposed in their 
surroundings—say, dissolved in water—and free to 
move, and each atom hastens to don his electrical 
charge and deploy to a strategic position. The metals 
in general rally to the positive cause, the non-metals 
to the negative. But here, as in many another con- 
flict, there is bound to be some disaffection in the ranks. 
Some companies go at it with great singleness of pur- 
pose, determined to neutralize every opposite charge 
in the neighborhood; others are of two, or three, or 
four minds about the matter, and are rather neutral in 
their behavior. 

We cannot here go into the characteristics of all the 
elements, fascinating as they are in their almost in- 


172 THE STORY OF COPPER 


finite individualities. The point upon which we must 
fix our attention is their electrical behavior. We might 
skim over the valence, or combining power, or ‘‘elec- 
tive affinity,’’ of copper and the other elements by 
using such similes as may be drawn from a battle, as 
we hinted above, or from marrying and giving in mar- 
riage, but it is believed that something of the actual 
mechanism of chemical action will give a better con- 
ception of just what a compound is; and the actuality 
is so bizarre that similes pale in interest beside it. 
Let us look more closely at our rows of elements. 
Any one of them will do as a sample, and so we shall 
‘choose copper as the most interesting to us at the 
moment. We shall suppose our sample in the state 
in which we like to see it—beautifully regular in form, 
smooth of surface, and brightly polished. Suppose 
we look at it through a microscope. The surface that 
a moment ago seemed perfectly smooth now has the 
profile of rugged mountains and precipitous valleys. 
Its evenness was due only to our coarse perceptions. 
Taking for our aid a bit of magic,—whose lack 
causes scientists to go to all sorts of circuitous lengths 
to learn the things we shall now see,—let us take a 
fairy’s embroidery-needle and pick off a tiny pebble 
from one of the copper mountains our lens has re- 
vealed. Now we change the objective lens of our in- 
strument and magnify this speck in turn; what we see 
is a large number of shining balls, not packed together 
like shot in a box but flying about through space with 
a random moticn. Over here two seem about to have 
a head-on collision! Closer together they rush; then 
do a half-turn about each other and rush away in 


COPPER’S CHEMISTRY 173 


other directions. Here one coming straight toward 
the lens—for they travel in three-dimensional space 
—gives the opportunity to watch it a moment longer 
than the others. While it travels it is spinning, spin- 
ning, without incitement, without end. Look with the 
other eye over the frame of the instrument. The 
system that contains this eternal tireless motion is 
just an ordinary lump of hard, cold, inert metal. 
Of course, you identify the flying spheres which you 
have just seen as atoms. Now no man has ever yet 
looked down the barrel of a microscope and seen an 
atom. The limit of our vision, even with the most 
powerful lenses, is reached long before so infinitesimal] 
a thing can be brought into focus. Yet the student of 
these affairs knows far more about what atoms do and 
even what they look like than he does about many other 
things that go on in plain sight. From the time— 
only a little more than one hundred years ago—that 
John Dalton proposed the atomic theory, the conquest 
of the atom has proceeded at a rapid pace. The idea 
was, at first, that the atom is the ultimate particle, 
and beyond it nothing smaller can be. Let us catch 
one of our flying atoms, turn upon it the ‘‘fine adjust- 
ment’’ of our magic microscope, and see about this. 
We are looking at one atom. Behold, its oneness 
has vanished. We look to see something strange and 
novel, and we find only what we may see any clear 
night—a starry sky! There are not so many stars in 
this firmament, however. In fact, we have just one 
large solar system. And, looking at it more closely, 
it is different from the only other solar system we 
know—the one in which we live. In our system each 


174 THE STORY OF COPPER 


planet has its individual orbit; in copper’s atomic 
system, each orbit is shared by a number of planets 
which keep at regular distances from each other. 
There is another difference, toc. Jupiter and Venus 
and Saturn and Mars and the earth and the asteroids 
and all the members of our solar family have their 
orbits in virtually one plane. One could look at our 
system edgewise and imagine all the planets running 
around on a disk, perhaps something like balls on a 
roulette wheel. Copper’s system is more what we 
should expect to find in our three-dimensional uni- 
verse, for the orbits of all its planets, taken together, 
outline a sphere, or, better, an ellipse. 

The modern scientist, strangely enough, knows not 
only how these sub-atomic structures look but what 
they are made of; and, although they make up the 
material universe, they are not matter. This sounds 
like the adventures of that immortal pair, the Walrus 
and the Carpenter, doesn’t it? The lines might run 
something like this: 


We found each atom looking like a hard and shiny ball, 
And that was very odd because they are not things at all. 


Well, to end the suspense, they are electricity. The 
planets or electrons in their orbits are, apparently, 
eranular masses of negative electricity ; and the atom’s 
sun, or nucleus, at the center of the system, is com- 
posed of positive electricity, and also, from the evi- 
dence that has been gathered recently, of a corpuscular 
nature. We know that every one of the elements, 
pursued down to its sub-atomic structure, is made up 


COPPER’S CHEMISTRY 175 


in exactly the same way. For the actual spacing of 
the electrons it is necessary to resort to hypothesis. 
If we consider the known facts about atom structure 
we find that the main items are as follows: All ele- 
ments are made up of the same units, namely, grains 
of positive and negative electricity; each element has 
its own definite unit-weight, which is expressed as so 
many times the weight of an equal amount of hydrogen, 
the lightest of them. If the elements are arranged in 
the order of their atomic weights the properties by 
which we distinguish them vary by gradual change 
from those of one element to the next until the whole 
series from one kind of properties to a kind exactly 
opposite has been completed, and then the series 
swings back again. The latter statement is known as 
the Periodic Law, and is one of the most important 
generalizations that has ever been made in the field 
of science. The chemist phrases it, in his concise lan- 
guage: The properties of the elements are periodic 
functions of the atomic mass. In addition to the above 
demonstrable facts, we have excellent reasons for be- 
heving that we know the exact number of electrons in 
the atom of each element, or at least a submultiple of 
it; and we strongly suspect that the weight, or mass, 
of each element is so concentrated at the nucleus that 
the mass of the electrons is inconsiderable beside 
at? 

The terms of the problem are now stated. We have 
a number of heavy blocks, all alike, and a number of 
light blocks, also identical. By placing one or more 
heavy blocks together, and arranging around this 
group in three dimensions, varying numbers of the 


176 THE STORY OF COPPER 


light blocks, we must construct about ninety figures 
which shall differ not only in the weight of the whole 
figure but in some other manner which will account for 
the differences in properties of the elements. The so- 
lution is obvious. The figures must differ in the ar- 
rangement of the blocks. Therefore the arrangement 
of the electrons about the nucleus must account for the 
chemical properties of the elements. From this, one 
would expect elements resembling each other to have 
a similar arrangement of electrons. How shall we 
find out just what these arrangements are? We might 
try an analogy. There is a classical experiment often 
performed in connection with the study of magnetism. 
A number of ordinary steel sewing-needles are mag- 
netized, and each one is pushed through a cork. All 
are then floated in water with the same pole—for ex- 
ample, the positive—sticking up. The small magnets 
are then free to move in two dimensions, on the sur- 
face of the water; and, of course, the repulsion of the 
similar poles keeps them at an approximately equal 
distance from one another. They will accordingly 
form the geometrical figures most stable for the num- 
ber of needles used. Four, naturally, will place them- 
selves as the corners of a square. More can form cir- 
cles, but soon there are too many to stay in the ring 
comfortably, and one takes its place at the center. 
Large numbers of the needles tend to form concentric 
rings, where each outer ring holds more needles than 
does the one inside it. These figures represent the 
most stable forms for the interaction of the forces 
present. It will readily be imagined that particles 
such as electrons, repellent to one another, yet held 


COPPER’S CHEMISTRY viet 


near one another by some central attracting force, 
will assume similar space relations. The only dif- 
ficulty in showing exactly how they look in three di- 
mensions is the impossibility of allowing the models 
perfect freedom of motion. However, mathematical 
calculations of the probable arrangement can be made, 
which show that the principle of the grouping is much 
the same except that the rings of the above experiment 
become hollow concentric spheres or shells. This idea 
of spatial configuration has been elaborately worked 
out by G. N. Lewis and Irving Langmuir to account 
for the properties of the individual elements. 

If we are to build up element after element by con- 
tinually adding electrical particles to the preceding 
ones, it is obvious that the same configuration of elec- 
trons may serve for many elements, and that the atom 
of a relatively simple element may act as a sort of 
core for a more complex one. A little while ago we 
left the group of inert gases with the promise that we 
would return. Let us now consider them from the 
point of view of atom-pattern. The first of them, 
helium, is the second lightest atom known. We have 
reason to believe that its atom is made up of a nu- 
cleus and two electrons. The fact that the substance 
is inert is explained, according to the theory, as the 
result of perfect balance of the forces within the atom. 
The picture which at once presents itself is of one elec- 
tron on each side of the nucleus. That is, no doubt, 
the real arrangement. The system is so extremely 
stable that the helium form is the inner core of every 
heavier element. Itis not helium as such that is there. 
Hivery succeeding element has more positive particles 


178 THE STORY OF COPPER 


in its nucleus than has the lighter one before it. But, 
with the exception of hydrogen, which owns but one 
electron, every element has those two electrons holding 
each other in checkmate as its inner shell. We may 
imagine that, in the shake-up caused by some atomic 
catastrophe, two electrons might seize a sufficient num- 
ber of positive particles from the nucleus and emerge 
as helium. Something like this, indeed, does occur in 
the case of radium and many other radioactive sub- 
stances from which helium is given off as they disin- 
tegrate. The residue, having both the number of its 
particles and their arrangement changed, has thereby 
become transmuted into another element. 

But if we are to have more than two elements we 
must add another electron to the helium arrangement. 
It is understood that more positive units are added to 
the nucleus as we proceed, but since they do not affect 
the structure they need not be mentioned. We may 
easily imagine a stable arrangement of three electrons 
in an atom, but that configuration appears not to ex- 
ist in nature. Instead, the new electron betakes itself 
out beyond the first two and starts a new spherical or- 
bit, or shell. 

If balance of forces and relative immobility of elec- 
trons accounts for the properties of an inert chemical 
substance, the new element with a solitary electron in 
its outer shell should be chemically active, and so, in 
fact, it is—the metal lithium. But the next one, with 
another electron, would be less active, and this theory 
is also borne out by the metal beryllium. It might 
be just as inert as helium but for the fact that the 
second shell of the atom is larger than the first and 


COPPER’S CHEMISTRY iD 


consequently can hold more electrons. As a matter of 
fact, it holds eight, and not until all eight are present 
will the character of helium reappear. When three 
electrons enter the second ring of the atom, we get the 
element boron, parent of our familiar borax and boric 
acid. Its activity, as we should expect, is less than 
that of beryllium, its predecessor. With the next, 
carbon, the shell is half full. A certain balance, al- 
though not complete, would be expected. And indeed, 
its properties form a turning-point for the elements of 
this series. The preceding ones are of the type known 
as positive. If they are free to move in an electrical 
field, they seek the negative pole, because unlike 
charges attract each other. The elements following 
carbon are negative and are acid-forming substances. 
Their chemical activity increases now until we reach 
fluorine, the seventh element beyond helium, which dis- 
plays the climax of chemical activity for negative ele- 
ments. Beyond fluorine comes neon, twin of helium. 
The second shell of the atom has been filled. 

If we were constructing an imaginary figure from 
concentric spheres, we should certainly make the third 
shell larger than the second. But nature does it dif- 
ferently. The next sphere, beginning with neon and 
ending with chlorine, also contains eight elements, and 
each one of them repeats the fundamental properties 
of the element in the corresponding place in the pre- 
ceding series. 

The relationships between the elements were dis- 
covered about sixty years ago—long before an electron 
was even dreamed of. The Russian chemist Mendele- 
jeff formulated a table showing how the transition in 


THE STORY OF COPPER 


180 


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SLNAWATA IVOINGHO JO WIAVL OIGOIddd AHL 


COPPER’S CHEMISTRY 181 


properties is related to the atomic weights. Part of 
this table is shown herewith. The ‘‘Periodie Table’’ 
is vastly useful, but its peculiarities are just beginning 
to be understood. The elements beginning with helium 
are written in a horizontal line which ends with fluor- 
ime. Then the inert neon is written at the beginning 
of a second line and placed just below the inert helium. 
The active, very positive sodium comes next, right 
under the still more active lithium, and so on until 
chlorine finds its rightful place under fluorine. 

When he had got so far, we may well imagine that 
Mendeléjeff was sure he had the key to the universe. 
But the fascination of science lies in the fact that the 
solution of one problem only leaves us face to face 
with a greater one to tempt us on. The next problem 
in the relationship of the elements comes in the very 
next line. Series 3 of the table starts off just as usual 
with four quite predictable elements. The first four 
differ no more in their properties from the first four 
of series 1 and 2 than those series differ from each 
other. But following them comes a long list of ele- 
ments which not only fills the table twice but flows over 
into an extra group, and this group holds not one ele- 
ment, like the others, but three. Nevertheless, the plan 
which series 1 and 2 follow has not been totally aban- 
doned, for the last three elements of this ‘‘first long 
period”’ tally with the last three of the first two series. 
A second long period follows the first, and corresponds 
with it member for member. Chemists have always 
been rather irritated by these long periods, and partic- 
ularly by those Group VIII trilogies. The explana- 
tion of that Gordian knot in the middle of a long string 


182 THE STORY OF COPPER 


of metals has been too much of a puzzle. Group VIII 
has been nicknamed the ‘‘hospital for the incurables.’’ 

Before taking up the problem of the Group VIII 
triplets, however, we must fix firmly in mind the fact 
that most of the elements never exist uncombined. 
Copper, silver, and gold, and the gases of the air are 
the only elements that at all commonly occur native. 
The existence of the other elements in elementary form 
is due to the work man has expended on their ores. — 
As soon as he relaxes his vigilance, back they go into 
combination again. If we carry this thought down to 
our consideration of the atom, it must appear that two 
or more dissimilar atoms can together, in such cases, 
effect a more stable arrangement of electrons than 
ean one atom alone. And if we remember that when 
a compound is dissolved in water its molecule splits 
up into the positive and the negative components, each 
carrying an electrical charge, the whole mechanism of 
compound forming is clear. The electrical charge 
comes from the one or more electrons that the atoms 
shared in the molecule. When the compound dissoci- 
ated in the water these electrons went with the wrong 
half. The charge represents the desire of the one to 
give back the electron and of the other to get it. 

If an elementary nucleus is so little attached to an 
electron that it will lend it to any other element that 
will take it, there must be a very unstable structure- 
pattern in its atom. The elements of Group I fulfil 
Just these conditions. We have seen that they have 
each just one more electron than the very stable Group 
O element just before. If an atom of lithium can 


COPPER’S CHEMISTRY 183 


‘“‘lose’’ one electron, the remaining ones form the pat- 
tern of the inert helium. And if it can lose this elec- 
tron to a very negative element, like fluorine, which 
needs just one electron to assume a form as stable as 
neon, it is decidedly to the advantage of both elements 
to combine. Of course, they do not form a mixture 
of two inert gases. It is the form and not the sub- 
stance that is changed. What these two very active 
elements do form is a nicely crystallized, colorless salt, 
with a very high melting point (801° Centigrade) and 
other evidences of great stability. 

And now for the solution of the Group VIII mys- 
tery. These metals lie exactly in the middle of the 
long periods. Their electron patterns are quite as 
regular in form as those of the Group O elements. The 
fact that the shells do not contain their full quota of 
electrons prevents their being chemically inert, but 
their near neighbors in the Periodic Table tend to 
assume their form by gaining or losing electrons much 
after the manner of sodium and fluorine in reverting 
to the inert form. Neon and argon, each with eight 
electrons in the outer shell, have the cube as their 
atom-pattern, with an electron at each corner. Iron, 
with eight electrons in its outer shell, has the same ar- 
rangement. In this atom the diagonals of all three 
cubes coincide. Cobalt and nickel, the other members 
of the group, find but a simple modification of this 
structure necessary to take care of their one and two 
extra electrons. Cobalt places its over one face, mak- 
ing a sort of obelisk with square sides and a pointed 
top; nickel adds an electron over the opposite face 


184 . THE STORY OF COPPER 


and forms a square-sided prism, pointed at both ends. 
Iron, cobalt, and nickel are very much alike in the 
kind of compounds they form. 

Copper begins to break away from this influence. 
Its struggle to do this gives rise to some curious prop- 
erties. It was placed long ago in Group I of the table, 
and there are many reasons for having it there, but 
on the other hand it differs in dozens of respects from 
the earlier inhabitants of this section. Heretofore the 
break between the right-hand and the following left- 
hand groups in the table has been sharp and sudden. 
In the long periods it is gradual, and copper may 
well be considered a transition element. Fluorine and 
sodium, with neon between, have almost nothing in 
common. We might fancifully describe neon as bear- 
ing the relation to fluorine and sodium respectively 
that the cocoon does to the worm and the butterfly. 
It is the transition between two quite unlike forms. 
But copper reminds one of the Hindu idea of a trans- 
migratory creature which carries the mark of the old 
life on into the new. 

And so we find copper leading a double chemical life. 
As ‘‘euprous’’ it fits into the same category as sodium, 
losing one electron, or ‘‘acting with a valence of one.’’ 
Many of its compounds are colorless, as are those of 
all alkali metals. On the other hand, as ‘‘cupric,”’ its 
characteristics revert to the highly colored salts of 
the metals that precede it, and we find its principal 
salts displaying the green and blue colors with which 
we are most familiar. Colors of salts, caused as they 
are by vibrations of electrons within the atom, furnish 
a fascinating check for theories about the probable 


COPPER’S CHEMISTRY 185 


stability of atom structures. So we see that, although 
the cupric salts are the more usual, the cuprous com- 
pounds, with their paler colors, fore-shadow the pat- 
tern by which the following elements will be built. 


CHAPTER VIII 
COPPER’S JUNIOR PARTNERS 


No matter how extensive the qualifications of a per- 
son and regardless of his accomplishments along cer- 
tain lines, there are many things that he can do better 
if he cooperates with other people. Copper, despite 
its high qualifications for conductivity and other per- 
formances when it is strictly alone, can achieve many 
of its ambitions better if it has the cooperation of some 
of the other metals. For this reason alloys, or metal- 
lic partnerships, are formed every day. Fortunately 
copper is a very good mixer in metallic affairs, and 
there is hardly a metal with which at some time or 
other it does not go into business to perform a certain 
task. In its ability to cooperate it is superior to most 
people. 

The most frequent junior partners of copper are 
zinc and tin. Copper and zinc trade under the gen- 
eral firm name of ‘‘brass,’’ and copper and tin form 
‘‘bronze.’’?’ Hach metal does not always contribute 
the same amount of capital to the partnership for 
each venture, but new combinations are often formed 
for each undertaking. Of course there are a series of 
standard partnership agreements that are used when- 
ever possible, but when special occasions require it 
special agreements are often entered into. Alumi- 


num and nickel are two other partners of copper that 
186 


COPPER’S JUNIOR PARTNERS 187 


prove very useful, and the utility of aluminum, which 
is rather new to metallic business, is increasing as al- 
loys of it and copper are given experimental and prac- 
tical trials. Other metals alloy with copper fre- 
quently, but usually more than one other metal joins 
in the partnership. Three and four metals, including 
copper, are common in alloys, and at times copper is 
one of six elements joining together. These agree- 
ments and the way in which they are entered into are 
somewhat complex. Let us first content ourselves with 
seeing how the two-element partnerships that include 
copper as senior partner conduct their business. 

When two metals form a partnership, each one 
usually changes its habits somewhat and adapts its 
disposition so as to get along well with the other. The 
degree to which the resulting partnership acts as one 
or the other partner would act alone is, naturally, de- 
pendent upon the interest which each one takes in it. 
A combination of ninety-nine parts of copper and one 
part of zine we should expect to be very much like cop- 
per, and one of ninety-nine parts of zine to one of cop- 
per to be not very different from pure zinc. But when 
we observe something nearer a fifty-fifty agreement it 
is evident that each metal has tried to meet the other 
half-way. 

In order to get a general idea of the various contracts 
into which two metals may enter, let us leave ‘‘this 
bourne of time and space’’ and enter the country of 
metals whose map is printed herewith, a land where a 
new set of dimensions is in force. This is the solid- 
ifying region of the copper-zinc series, the land of 
brass. In it every possible combination of those two 


188 THE STORY OF COPPER 


metals has its place. Farthest to the left dwells cop- 
per when it is alone. The home of zinc is on the right- 
hand margin. The headquarters of the various part- 
nerships lie in the region between. 


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10 20 40 50 eo Bo 90 Joo Zine Fo 


CIRCLES eee THE con Seneeeee OF SPECIMENS 
SHOWN IN PHOTOMICROGRAPHS., 
MAP OF BRASS 


The curve which cuts off the upper right corner 
marks the lower boundary of the region where these 
metals can exist as liquids. The melting-point of pure 
copper is the point where this curve crosses the left- 
hand margin line. This temperature at which copper 


COPPER’S JUNIOR PARTNERS 189 


changes from liquid to solid is 1083 degrees Centi- 
grade (about 1981 degrees Fahrenheit). Zine melts 
at a temperature much nearer to those we are familiar 
with, 419 degrees C. (786 degrees F.). 

The copper-zince plane is a strange country to us, yet 
we can trace on the diagram the place where these sub- 
stances touch our daily lives. You observe that the 
straight lines crossing the page represent hundreds of 
degrees of temperature. The bottom line of the figure 
is zero on the Centigrade scale, the freezing-point of 
water. The next line, marked 100 degrees, is the 
temperature at which water boils. Our ordinary lives 
are spent well within these limits. The large black 
circles represent the composition of the principal types 
of brasses. Only a few of these are of great commer- 
cial importance. | 

Now, in order to appreciate the meaning of the vari- 
ous fields marked off below the solidifying line in the 
diagram, let us make, in imagination, an investigation 
of the alloys which copper and zine will form. We 
will take a number of crucibles and in each place a 
quantity of each of the metals. We are at liberty to 
mix the two in any proportion that we see fit, that is, 
we may vary the components. It will be interesting 
to try to cover the whole field, and so we may select 
101 crucibles and vary the composition by steps of 1 
per cent. The first crucible will hold pure copper, 
the second will blend 99 per cent. copper with 1 per 
cent. zine, the third will contain 98 per cent. copper 
and 2 per cent. zinc, and so on, until the last one will 
have no copper and 100 per cent. zinc. Let us now 
heat all the crucibles until the metals have melted and 


190 THE STORY OF COPPER 


the mixtures have become thoroughly blended. We 
cannot heat them all in the same furnace, for the zine 
would boil away to vapor before the copper melted, 
but we can imagine such details all nicely adjusted in 
a series of furnaces, so that we can allow the contents 
of one crucible after another to cool down while we 
watch the process and the indicator which shows the 
temperature at which the changes happen. The first 
crucible to show any change will be No. 1, containing 
copper alone. A trifle above 1080 degrees the bright, 
molten metal will begin to freeze over on the surface, 
especially around the edges. And now we notice a 
peculiar thing. The pyrometers which are measuring 
the heat of the other crucibles will show that their 
temperatures are gradually falling, but, so long as the 
copper is solidifying, the one connected with Crucible 
No. 1 will register a constant temperature. It is char- 
acteristic of chemical elements and compounds that 
they freeze and melt sharply at a single point. What 
substances that are not elements or compounds do is 
by this time being demonstrated by Crucible No. 2, in 
which 1 per cent. of the copper has been replaced by 
zinc. This material began to harden a little below 
copper’s freezing-point, but its temperature did not 
remain quite constant. It had cooled off a few degrees 
before the last of the alloy became a solid. Crucibles 
3 and 4 and 5 and so on have been behaving in the 
same way in the meantime, and in some cases the tem- 
perature has dropped more than fifty degrees while 
the melt was becoming solid. Those alloys contain- 
ing up to 30 per cent. zinc have now been cooled be- ° 
low their freezing-points, Let us pause a moment 


COPPER’S JUNIOR PARTNERS 191 


here and see just what we have found out. The tem- 
peratures at which the alloys have solidified have, so 
far, decreased as the percentage of zine became great- 
er. They have followed the upper, heavy curve in 
the diagram. That line, then, gives the freezing- 
points of the alloys. But, instead of a definite point 
at which they freeze all at once, we found that they 
may cover quite a range of temperature in that in-be- 
tween. state. The temperature at which they stop 
freezing and become entirely solid is, therefore, im- 
portant, too. If we plot that temperature for each of 
the alloys, we find that we have drawn the lower curve, 
the dotted line in the diagram. If now we were to 
heat the alloys up again, we should find them begin- 
ning to melt at the lower point and becoming entirely 
liquid at the upper. The upper line, then, bounds this 
melting state on the liquid side, and the lower is its 
boundary on the side toward the solid region. The 
names of these lines, ‘‘liquidus’’ and ‘‘solidus,’’ are 
obvious in meaning. 

It is always interesting to find out what a substance 
that we have made looks like. As soon as our high-cop- 
per brasses have cooled down enough so that we can 
distinguish their color, we find a series of gold-colored 
metals, varying in shade from that of their parent cop- 
per toward the well-known brassy yellow. The alloys 
which contain 10 to 20 per cent. zinc look especially 
like gold, and are known under various names, such 
as tombac, Manheim gold, pinchbeck, French oreide. 
Such metal can be cast and stamped, and is used 
mostly for ornamental work. It is not unlikely that 
this material was made by the alchemists in their at- 


192 THE STORY OF COPPER 


tempts to refine copper to gold, and palmed off, either 
sincerely or fraudulently, on the poverty-stricken 
princes of Germany who were the alchemists’ most 
hopeful backers. 

To the metallographers, the allege we have just 
mentioned are all the same substance, known to them 
as ‘‘component alpha.’’ Although they are of differ- 
ent chemical composition, and have very different 
physical properties, they are identified by a common 
appearance when examined through a microscope. 
The study of the microscopic appearance of metals is 
one of the important newer sciences which has un- 
locked for man the door to the understanding of phe- 
nomena that go on just beyond his ken. After etching 
the metal to remove the surface skin, the pattern of 
crystal structure is studied under a medium-high mag- 
nification. Some alloys are found by this means to 
be homogeneous substances. Others consist of mix- 
tures of two distinct types of metal. In such cases, 
one usually crystallizes out first, and appears as little 
islands in a matrix of the second alloy. Alpha is one 
of the homogeneous alloys, and a picture showing the 
nature of its crystal structure is shown in _ Photo- 
graph A. 

To return to the constitution diagram of the brasses, 
and our imaginary experiments, we find that when we 
examine those alloys which contain around 60 to 40 per 
cent. copper a different sort of metal has resulted 
from the fusions. The liquids in this series of ecruci- 
bles have had to be cooled still more before they would 
solidify. The color of the cooled products is more 
yellow than the reddish or gold-colored alloys in the 


Courtesy of National Bureau of Standards 


STRUCTURE OF VARIOUS BRASSES (COPPER-ZINC ALLOYS) SEEN 
THROUGH MICROSCOPE, MAGNIFIED 100 TIMES 


The proportion of copper and zinc in the photographs varies as shown on the 
constitutional map of brass, where the circles, left to right, designate the com- 
position of brasses from ‘‘a’”’ to ‘“‘h.” ‘“‘A,’” “‘c,” “fe,” and “‘g’? are simple in their 
structure, while the other four alloys are duplex. ‘‘A”’ is composed of alpha brass 
and ‘“‘c’” is beta brass. ‘‘B’”’ is a cross between “a” and “c,” the dark portion is 
beta brass while the light is alpha. “‘E”’ is gamma brass and the dark splotches in 
“d’’? are gamma; the light background is beta as in ‘‘c.” ‘“F’’ is a mixture of the 
gamma of “e’’ and the darker epsilon brass of “g.’’ The light, fern-like material in 
“th” is also epsilon brass, and the remaining black portion is zinc-rich eta, which is not 


pictured separately. 


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COPPER’S JUNIOR PARTNERS 193 


former series. The properties of these brasses are 
quite different from those composed of the alpha com- 
ponent. While the brasses, made of alpha, can be 
drawn into tubes and wires when they are cold, this 
new series of brasses have very little ductility in the 
cold, and must be drawn or rolled at least partly at 
high temperatures. <A glance at the diagram will ex- 
plain this property. Alloys of the compositions men- 
tioned cool to form a different component, or phase, 
from those with higher copper content. It is called 
‘‘beta.”’?’ But it is not an entirely stable form at 
lower temperatures. The field in which it is at home 
dwindles as the temperature falls, and soon some of 
the beta changes to the alpha phase. If the brasses 
are heated up to the temperature at which they be- 
come almost or entirely beta, the working of the metal 
is made much easier. You begin to see now the 
value to the metallurgist of having a map of the whole 
region which his metals may inhabit. But although the 
beta phase is not stable at common temperatures, and 
tends to change spontaneously into alpha or gamma, 
it requires a definite amount of time to make these 
changes, and so, by cooling the alloy suddenly from a 
temperature natural to beta, above 750° C., we can 
catch the pure beta form and transport it to conditions 
where we can study it. Photograph C shows what 
pure beta looks like, and Photograph B shows the ap- 
pearance of an alloy cooled from the region ‘‘alpha 
plus beta,’’ where the islands and peninsulas of red- 
dish alpha lie scattered quite thickly on the yellow sea 
of beta. Photograph D shows the microscopical struc- 
ture of the alloy into which beta containing between 


194 THE STORY OF COPPER 


65 and 40 per cent. copper changes when it is cooled 
to room temperature. Beta is again the matrix in 
which the other component has segregated, but the 
network is a new phase, gamma, whose color is 
silvery-gray. E is a picture of gamma alone. It is 
evident that with this phase zinc is getting the upper 
hand in the combination. The colors of the alloys al- 
pha, beta, and gamma have by this time gradually 
faded from the red of copper to the colorlessness of 
zine. 

The other brasses indicated on the diagram as 
‘‘epsilon’’ and ‘‘eta’’ are not of commercial impor- 
tance. Photograph G shows the structure of epsilon 
of the composition indicated by the second black cir- 
cle from the right on the diagram. ‘The last circle on 
the right-hand side is in a region where epsilon and 
eta exist together. Eta forms the matrix in this alloy, 
pictured in Photograph H, while the crystals of epsilon 
can be distinguished for it by the purplish oer, of 
their silvery-gray. 

In looking back once more over the diagram as a 
whole, two curious points are to be noted. The first 
of them is at the composition 40 per cent. copper, 60 
per cent. zine, where the liquidus and solidus curves 
touch. This means that an alloy of that composition 
will melt sharply while the temperature stands con- 
stant at 833 degrees, just like a pure metal or a true 
compound, and it appears that a compound has really 
been formed, of the molecular composition Cu,Zng. 
We know very little about the exact mechanism of the 
formation of inter-metallic compounds, but it is evi- 
dent that numbers of them exist. Therefore we can 


COPPER’S JUNIOR PARTNERS 195 


distinguish three different sorts of alloys: true com- 
pounds like Cu,Zn,; homogeneous mixtures like alpha, 
which are called ‘‘solid solutions’’ of one metal in the 
other; and mixtures of two phases which are so clearly 
shown in Pictures B, D, F, and H. 

X-ray spectrum photographs have begun to show 
within the last few years how the atoms of the two 
metals arrange themselves in the metallic crystals to 
form the so-called solid solutions, like alpha brass. 
Atoms of zinc enter into the copper crystal and actu- 
ally replace some of the copper atoms. Further re- 
search will reveal more of the mechanism of such com- 
binations. 

The properties of alloys are in the main derived 
from those of the two metals which make them up, in- 
clining to the one present in greatest quantity. The 
melting-points of the brasses descend with lessening 
copper content from the melting-point of pure copper 
to that of zine, with one exception. An alloy which 
contains a very small amount of copper, lying on the 
boundary between the eta and the epsilon plus eta 
fields, is seen from the diagram to melt at a lower tem- 
perature than pure zinc. This anomalous behavior is 
shown by alloys and compounds fairly frequently. 
The substance which separates at this low tempera- 
ture is similar to a compound, for under the conditions 
at which it separates it solidifies at a constant point. 
It differs from a compound in some technical points, 
but it is a definite substance and is called the eutectic 
alloy. It will be observed from the other diagrams 
that eutectics are formed also by the bronzes and the 
aluminum bronzes. 


196 THE STORY OF COPPER 


The copper-tin and copper-aluminum diagrams are 
of the same type as that showing the copper-zine al- 
loys. In each of these series, it is the copper-rich al- 
loys that are important. Brass, bronze, aluminum- 


Hoo" 


100° 


oy 
= [o) . 
%Copper oe eo aes sh oA 50 100 geo 
0 


bite nike OF OOPPER-ALUMINUM ALLOYS 
bronze, and copper-nickel alloy are each essentially 
copper to which has been added an element whose 
properties add something which improves the red metal. 
for a specific use. 
It happens that the Bs at the other end of the 
diagrams do not have properties that make them par- 


= 


COPPER’S JUNIOR PARTNERS ibe 


See ||. | Le 
bows alse 


ea 


1500" 


1300 


ait 
ESBS 
Pahe 


1200 


ZCopper os 90° 80° 70° 60 SO : : 
40° 30 20° ° 
° to 20 30 40 sO 60 70 BO $0 lOONickel% 
MAP OF COPPER-NICKEL ALLOYS 
1. Driving bands for shells 8. Nickel coin 


2. Bullet jackets 4, “Constantan,” used in thermo- 
couples and elec. resistance 


198 THE STORY OF COPPER 


ticularly valuable. If they did, the important ones 
would contain from about 30 per cent. copper down. 
It is seldom that a fifty-fifty partnership between 
metals is very successful. It is a general rule among 
metals that alloys made up of two metals in about 
equal proportions are too hard and brittle to be of 
much commercial importance. 

The diagram of the copper-nickel alloys, although 
it appears at first glance so astonishingly simple, 
shows several interesting differences from those of 
the other common copper alloys. It alone of the four 
here given shows copper associated with a metal of 
higher melting-point than its own. Nickel’s melting- 
point is more than 300 degrees Centigrade higher than 
that of copper. It will be noted that the liquidus and 
solidus curves are continuous between the two ends, 
with no humps or points. No field boundaries lend 
complexity to the figure, except at the lower right-hand 
corner, and that curve means merely a change in the 
structure of an already homogeneous solid to another 
homogeneous form. This shows that copper and 
nickel form a continuous series of solid solutions. 
Nearly all of the resulting alloys are white. Copper 
can impart its striking color only when it makes up 
more than about 85 per cent. of the metal. It must 
not be thought, however, that all these white alloys 
are the same. Their structure appears alike under the 
microscope, but their properties vary as the composi- 
tion changes. All are very malleable, but, in accord- 
ance with the general rule, the fifty-fifty alloys are 
found to be tougher and harder than are the others. 

If the other metal that joins with copper in a part- 


COPPER’S JUNIOR PARTNERS 199 


nership is unlike it in its physical and chemical prop- 
erties, the intensity of the effect of its addition is 
greater in a general way. Thus, tin is more different 
from copper than zinc, and as a He eA H bronze 


VATS om oS6 og: of ° 
ol oe ce cas daddo 9) of, 


See eee eee e. 
- cam dha 
ied rol et 
oa 

See nee at 
CREEL 
[ alleen Da ame) Yr |_|” | 


MAP OF BRONZE 


1. Coinage bronze 

2. Gun metal 

3. Bell metal 

4, Speculum metal—formerly used for mirrors é 
has properties more foreign to copper than has brass. 
Rosenhain, the English metallurgist, noted also that 
the intensity of effect is oppositely proportional to the 
solubility of the added element in the copper, when 
the solubility is reckoned in terms of relative number 


200 THE STORY OF COPPER 


of atoms. The atomic solubilities of zine, aluminum, 
and tin in copper are 36, 14, and 6.7, and the increase 
in hardness and the decrease in ductility caused by 
an addition of these metals to copper are in the in- 
verse order of their solubilities. Thus, brasses, com- 
binations of copper and zine, are softest; bronzes, 
combinations of copper and tin, are hardest and least 
ductile; and the aluminum-copper alloys lie in between 
in properties. 

Though the brasses are more often and widely used 
in the world to-day, in point of time the bronzes sur- 
pass the brasses. The old pieces of bronze that have 
been dug out of Egyptian tombs may be nearly twice 
as old as the most ancient piece of brass. As we have 
seen, tin was alloyed with copper shortly after cop- 
per was discovered and appreciated. Not until early 
Roman times did zine appear as a principal and in- 
tentional constituent. If you have indiscriminately 
read the literature of the ancient world, you may doubt 
the truth of the fact that brass was not used until only 
a few years before the birth of Christ. In the Ho- 
merics, in the Bible, and in the other writings of the 
early world that have survived you will read ‘‘brass’’ 
many times. The reason for this is that tm and zine 
were not clearly distinguished until much later times, 
and in those days alloys of copper and tin and copper 
and zine were both called brass. Much early ‘‘brass”’ 
our metallurgists would properly call bronze. The 
Latiz word @s signifies either pure copper or bronze, 
but the Romans did recognize a brass compound of 
copper and zine under the name of orichalcwm or aurt- 
chalcum, 'The confusion of brass and bronze was ram- 


a 


COPPER’S JUNIOR PARTNERS 201 


pant during the middle ages and it even exists to-day, 
although now a brass alloy is technically but incor- 
rectly called a bronze in commercial usage in some 
cases when it has a distinguishing and special third 
metal. Exact knowledge of the copper alloys is of 
comparatively recent origin. The first nearly com- 
plete survey of all the combinations of copper and 
zine was only made about twenty-five years ago, while 
bronzes and the aluminum and nickel alloys have been 
investigated much more recently. 

So extensive are the alloys of which copper is a 
part that it takes thirty pages of the 1922 annual vol- 
ume of the American Society for Testing Materials to 
list their names and compositions. There are sepa- 
rate names for 280 alloys, grouped as brasses be- 
cause of the predominance of copper and zinc, and 
there are nearly as many bronzes. Nearly 500 alloys 
with nickel, aluminum, or manganese as junior part- 
ners and copper as the principal part are listed. 
There are about as many more of gold, silver, alumi- 
num, and other metals in which copper plays a 
strengthening, but minor, role. It would be uninter- 
esting to know the details about all of these. Let us 
find out about the general classes of partnerships. 

As we have seen from our travels in the land of 
brass, where partnership of copper and zinc reigns 
supreme, brasses can be of any proportion of the two 
metals. In commercial circles, however, only the com- 
bination containing more copper than zine proves to 
be eminently successful. The usual range is from a 
90:10 to a 60:40 mixture, but most successful and use- 
ful are the alloys with from 80 to 60 per cent. copper. 


202 THE STORY OF COPPER 


‘‘Red metal’’ is the name given a rich copper combina- 
tion of 90:10, and the alloys of this general proportion 
are used as substitutes for gold in cheap jewelry; 
80:20 brass is called low brass and sometimes ‘‘bell- 
metal,’’ although the latter term generally means a 
bronze that is better suited for bell-making than the 
brass. ‘The favorite proportions of brass for making 
tubes and wire is 70 per cent. copper and 30 per cent. 
zinc, while standard sheet-brass is a 66:34 combina- 
tion, which is also the alloy most frequently used for 
castings of brass. Brasses which contain more than 
67 per cent. copper are made up entirely of alpha brass 
and are sufficiently ductile so that they can be worked 
cold, but great care must be used in annealing so that 
strains caused by the working will not be left in the 
metal and cause a failure in later life. The brasses 
with lower amounts of copper, ranging from 55 to 63 
per cent., are used in operations that require hot roll- 
ing or extruding. The ductility of these brasses is 
very low when they are cold. If you remember, brass 
of this composition when cold is composed of both 
alpha and gamma brass, according to the constitution 
diagram of brass. When it is heated, at one tempera- 
ture interval it changes to homogeneous beta brass 
which is easy to roll and work. The approximately 
60:40 brass has a full yellow color and is sometimes 
called yellow metal. More often it is named after 
G. F. Muntz, who invented it in 1832 in England, or, 
instead of ‘‘Muntz metal,’’ ‘‘patent metal’’ is the term 
used sometimes for the same reason. Muntz metal is 
a very useful and reliable alloy under most circum- 


COPPER’S JUNIOR PARTNERS 203 


stances, though it has one failing. In some sorts of 
water, particularly water that is acid, it will corrode. 

For sea use, brass usually can be protected against 
disintegrating if a little of the capital of tin is called 
into the partnership and the working arrangement is 
made ternary instead of binary. The firm name of 
such an arrangement of about 61 per cent. copper, 38 
per cent. zine, and 1 per cent. tin, is ‘‘naval brass.’’ 
A little tin entering into virtually any brass usually 
makes it a little better. Several other names are ap- 
plied to brasses with a small amount of tin used in 
marine work. Among these are ‘‘Tobin bronze’’ and 
‘‘pivot dise bronze.’’ Tobin bronze contains from 59 
to 63 per cent. of copper and from 14 to 114 per cent. 
of tin; the remainder is zinc. As the composition 
shows, these so-called bronzes are in reality brasses. 
This is only one example of the present-day confu- 
sion in metallurgical terms. The most flagrant case 
of mislabeling is ‘‘manganese bronze,’’ which is not 
a bronze nor does it contain manganese as an impor- 
tant constituent. The manganese part of the mis- 
nomer arises out of the use of ferromanganese or pure 
manganese as the lawyer or deoxidizer attending to 
the expulsion of undesirable oxygen from the partner- 
ship and making the founding of the firm easier. The 
‘‘hronze’’ part simply came from starting wrong, and 
the alloy has not been able to overcome the incorrect 
name. The compositions of manganese bronzes vary 
but may be listed as about: copper 58, manganese 0.3, 
zine remainder, with small quantities of tin from 0.5 
to 1.5 per cent., iron from 0.8 to 2 per cent. aluminum, 


204 THE STORY OF COPPER 


and lead sometimes amounting to several parts. Some 
true copper-manganese alloys are used, especially as 
stay-bolts for boilers in European countries. Tests of 
copper with additions of 6 to 8 per cent. manganese 
have revealed promising qualities. 
_ Lead added to brass improves its machining prop- 
erties and is very important in many industries. Lead 
does not show the same compatibility when mixed with 
copper and zinc that those two metals accord each 
other. The particles of soft lead stand off in globules 
and refuse to become intimate. The resulting solid is 
made up of lumps of lead scattered through the brass. 
The mixture, shown in the photomicrograph, looks like 
a piece of Schweitzer cheese. The cheese is the brass 
and the ‘‘holes’’ are filled with lead. Typical lead 
brasses are composed of 60 to 63.5 per cent. copper, 
390 to 33.5 per cent. zine, and 2 to 3.5 per cent. lead. 
Tin sometimes appears as a fourth component of lead 
brasses. 

Iron is often added to brass in small quantities to 
add to its strength, hardness, and toughness, as it does 
not destroy its ability to be worked, either hot or cold. 
Delta metal has a composition of 55 to 65 per cent. 
copper, 43.5 to 30 per cent. zinc, and up to 5 per cent. 
iron. Aitch’s metal, a similar alloy, has a 56:41.5:1 
composition. Fourth and fifth members of the brass 
firm are added in some cases to obtain special qual- 
ifications. Vanadium enters into a special Victor 
bronze: 0.03 per cent. vanadium, 58.6 per cent. copper, 
38.5 per cent. zinc, 1.5 per cent aluminum, and 1 per 
cent. iron. 


COPPER’S JUNIOR PARTNERS 209 


One of the most common examples of a bronze is 
the ‘‘copper’’ that you probably have in your pocket. 
Since early in the history of the world bronze has been 
a favorite coinage metal, and to-day millions of coins 
in all parts of the world are made of it. The composi- 
tion of the United States one-cent pieces is 95 per cent. 
copper and 5 per cent. zine and tin, the relative quan- 
tities of tin and zinc varying in different batches of 
penny materials. If coinage bronzes are not all cop- 
per and tin, 1 or 2 per cent. zine is often added, and 
the French coins contain some iron to make them hard. 
Gun-metal is the name that still clings to the alloy of 
about 90 per cent. copper and 10 per cent. tin that was 
once used in the manufacture of artillery. In most 
cases some zine is added in making gun-metal. The 
government specifications call for 88 per cent. copper, 
10 per cent. tin, and 2 per cent. zinc, and this metal is 
known as government bronze. ‘‘Bell-metal’’ is the 
name applied to the bronzes used in casting bells; they 
may range from 10 to 25 per cent. tin. The com- 
position of statuary bronze varies over a wide range, 
and zine and lead are added to give it better casting 
qualities and enhance the valued patina that statues 
take on with age. Either the zine or tin in any 
one alloy should be below 2 per cent. when the 
composition is: copper, 88 to 95 per cent.; tin, 2 to 
10 per cent.; zine, 0.5 to 10 per cent.; and lead up to 
2.5 per cent. A bronze called ‘‘speculum metal’’ that 
takes a very high polish has a tin content of about 
30 per cent. and because of its white color and surface 
was used as mirror material before looking-glasses 


206 THE STORY OF COPPER 


were perfected. Phosphor bronze, unlike the similar 
sounding brass, manganese bronze, is a true bronze, 
and, while the phosphorus that gives it its name acts 
as deoxidizer and by its cleansing action produces more 
fluid metal and sounder castings, it also enters into 
the partnership. By the use of phosphorus, strength 
of bronzes can be increased a third without materially 
lowering the ductility, because of the removal of the 
oxides. Phosphor bronzes contain in their composi- 
tion less than 1 per cent. of phosphorus in most in- 
stances. 

As material for bearings, modified bronzes are used 


extensively. Bearing metal must stand three tests: it 


must wear well, it must ‘‘give’’ sufficiently to carry 
the load evenly, and it must be strong enough to re- 
sist the weight. Copper-base metals are the strongest 
bearings in general use. Originally they were made 
of a simple alloy of copper and tin, but lead was found 
to add to the plasticity of the bearing. The soft metal 
is imbedded in a matrix of bronze dendrites forming 
a cushion. 

Standard bronze bearing metals contain from 5 to 30 
per cent. lead, and, although the results are not so 
good, zine is often added as a fourth component. In 
making machinery parts that are exposed to corrosion 
or that wear on each other with considerable friction, 


bronze is widely used. In the case of parts that rub, - 


the one that is most easily replaced is made of bronze 
and allowed to take all the punishment. Here is how 
copper is used in various compositions of machinery 
bronze: 


COPPER’S JUNIOR PARTNERS 207 


Compositions 
Copper Tin Zine Lead Antimony 
Eccentric rings | 84.0 14.0 2.0 
Dense alloy for pump-bodies 
and valve-boxes 88.0 10.0 2.0 


Whistles for locomotives 80.0 18.0 2.0 
Same with somewhat duller 

sound 81.0 17.0 2.0 

Stuffing-boxes, valve-balls 86.2 10.2 3.6 

Screw-nuts for large threads 86.2 11.4 2.4 

8.5 

2.0 


Piston-rings 84.0 3.0 4.5 
Distributing slide-valve 82.0 18.0 
Alloy for mathematical and 
physical apparatus but 
slightly subject to changes 
in temperature 82.0 13.0 5.0 
Alloy for more delicate 
weights, balances, and 
mathematical instru- 
ments 90.0 8.0 2.0 
Propeller blades and boxes 57.0 14.0 29.0 
Paddle-wheel pins 76.8 17.4 5.8 
Cog-wheels BULL Sik 9.0 
Special highlead bronze 70.0 GU on Tyo 
Babbitt, tin-base 
Babbitt for motor 3.7 Bo ar roth Staats 52 7.4 
bearings 1.0 S005 . voure ono 10.5 


Alloys are now made with copper that are very sim- 
ilar to the copper-tin bronzes that have been used for 
centuries, yet the like of them could never have been 
known if a young American chemist named Hall had 
not discovered a fairly cheap method of separating 
aluminum from its ores electrolytically. Aluminum 
and copper compete to a small extent in the electrical 
field, but as partners in the same alloy they get along 
very well. Aluminum bronzes, as copper-aluminum al- 
loys are called despite the fact that they contain no tin, 
were first produced in 1885 when the recently electro- 
lyzed aluminum was absorbed into copper. The usual 
amount of aluminum added to copper is from 3 to 10 


208 THE STORY OF COPPER 


per cent. But the possibilities of the general partner- 
ship of copper and this newer metal have not been in- 
vestigated as thoroughly as they might be, and we may 
expect to see a greater use for it in the future. Cop- 
per-aluminum alloys have strength, ductility, and re- 
sistance to corrosion, and can be worked both hot and 
cold, but they are costly, and difficult to melt and cast, 
owing to the liking of aluminum for oxygen and to their 
shrinkage. As junior instead of senior partner copper 
also enters into alloys with aluminum, forming from 
1 to 5 per cent. of such mixtures, and often working 
in conjunction with magnesium, manganese, nickel, or 
zine. 

Among the oldest alloys known to man are those of 
copper and nickel. They may even antedate or equal 
in age the better-known brass. Bactrian coins con- 
taining 77 to 78 per cent. copper and 22 to 23 per cent. 
nickel date from 235 B. c., and their composition is al- 
most identical with the modern nickel coinage alloy. 
Despite its antiquity the pure copper-nickel partner- 
ship has not come into the prominence that its un- 
usual properties should give it, although during the 
war its service on the battle-front served to stimulate 
interest in what it can do. As we learned when we 
surveyed the map of the copper-nickel partnership, 
these two metals dissolve into each other in all propor- 
tions, and unless there is more than 85 per cent. cop- 
per the front put up by the partnership is the same as 
nickel’s color. Some of the compositions of copper- 
nickel alloys now in common commercial use are: 
cupronickel, containing 2.5 per cent. nickel, used as 


COPPER’S JUNIOR PARTNERS 209 


material for driving-bands of shells; 15 per cent. 
cupronickel, used largely for bullet-jackets and by the 
United States navy; nickel-bronze, or coimage bronze, 
used for baser currency and containing 25 per cent. 
nickel; copper-nickel, containing 50 per cent. nickel, 
used for remelting in the manufacture of copper-nickel 
alloys; constantan, used as one element in the construc- 
tion of thermocouple pyrometers and also as electrical 
resistance wire, containing 45 per cent. nickel. A nat- 
ural alloy in which copper plays an important part is 
monel metal. This alloy consists of 67 per cent. nickel, 
28 per cent. copper, and 5 per cent. of iron, manganese, 
silicon, and other metals. It is produced from the 
Sudbury ores in Canada that have that composition 
after smelting and refining. Despite the fact that na- 
ture compounded this alloy in the earth many epochs 
ago, it was only in 1905 that it was first brought into 
metallic partnership by man and put to work in his 
service. 

Another nickel alloy that contains a major amount 
of copper is of very ancient origin and was known to 
the Chinese under the name of ‘‘packfong,’’ or white 
copper. In the course of time this partnership of cop- 
per, zine, and nickel acquired the*name of ‘‘German 
silver,’’ but during the War our patriotic citizens came 
to the conclusion that it was too useful and doing too 
valiant service in the War to wear a Teutonic name. 
So it was changed to nickel silver, which is only half 
right at that. A committee of the American Society 
for Testing Materials has suggested that the name be 
changed to ‘‘nickelene’’ to deprive the alloy of its de- 


210 THE STORY OF COPPER 


ceptive label, but it seems likely that users of the metal 
will continue to prefer the richer sounding name of 
nickel silver. In truth, it is a nickel brass. The vari- 
eties of nickel silver are legion, but their compositions 
will vary usually within the following limits: copper, 
02 to 80 per cent.; zine, 10 to 35 per cent.; and nickel, 
0 to 30 per cent. The proportions in commercial use 
are: 


Material Nickel Copper Zine 
Cutlery and knife stock 15-25 55-65 14-20 0.5-1.5 Iron 
Key stock 8-18 55-65 15-35 1-2 Lead 
Jewelers’ wire 5-25 53-63 25-32 ee 
Brazing solder 8-20 35-40 40-55 ape 
Watch-case metal 10-28 55-65 16-30 0-1 Lead 
Spoon and fork stock 10-20 57-66. 20-30 Anh 
Platers’ bars and cores 5-25 56-70 18-24 


Copper, nickel, and zine are combined in many dif- 
ferent proportions to form nickel silver, but there is 
a separate name for nearly every different composi- 
tion. A few of the aliases of the copper-zinc-nickel 
partnership are: extra white metal, white metal, argu- 
zoid, best best, firsts or best, special firsts, seconds, 
thirds, special thirds, fourths, fifths, for plated goods, 
alfenide, alpakka, amberoid, argentan, argentan solder, 
argentin, argiroid, argozoil, arguzoid, argyrolith, 
aterite, carbondale silver, Colorado silver, China sil- 
ver, craig gold, electroplate, electrum German silver, 
Keens alloy, Lutecin. Maillechort, Markus alloy, neo- 
gen, Nevada silver, new silver, nickelin. These alloys 
are largely used as substitutes for silver and as base 
metals for plated silverware of all sorts. As their 
color is very similar to that of silver they can per- 


Tt tg age ae ee 


COPPER’S JUNIOR PARTNERS 211 


form this task well. Lead often becomes a fourth mem- 
ber oi the alloy when the metal is to be machined dur- 
ing manufacture. 

If I tell you that copper is used in the manufacture 
of jewelry, you will probably first think of the five-and- 
ten-cent store and its array of baubles. In that brass 
copper is contained, to be sure. But in the proudest 
wedding-ring and the most valuable. brooch there is 
some copper. Gold is not usually 24 carat, that is, 
100 per cent. pure. Some copper is added to take the 
gaff of every-day wear. Very rich gold contains only 
copper as an alloying metal, but those below 18 carat 
also have silver added. The universally accepted 
formule for the various alloys of gold, expressed in 
parts out of 24, are: 


Parts of 
Gold Silver Copper 
Carats (K.) 
22 


22 0 2 

20 20 0 4 
18 18 1 5 
16 16 1 7 
14 14 2 8 
12 12 2 10 
8 8 3 13 
6 6 4 14 


Silver as well as gold appreciates copper’s superior 
wearing qualities, and copper is added as a hardener 
to silver for use in jewelry and plate. The famous 
sterling silver is made up of 7.5 per cent. copper and 
92.5 per cent. silver, while enamelers’ silver is slightly 
richer, with only 6.5 per cent. copper. 

In the literature of the Romans and in classical writ- 
ings, Corinthian bronze was loudly extolled for its 


212 THE STORY OF COPPER 


great excellence and beauty. This statuary metal was 
so artistic and beautiful that the Romans could hardly 
believe that it was compounded out of mere base metal, 
Pliny, carried away by his laudations, states that the 
alloy was discovered by the Romans at the sack of 
Corinth, when vessels of gold, silver, and bronze had 
been accidentally melted together during the burning 
of the city and produed a golden bronze. It happens 
however that the siege of Corinth occurred in 146 B. c. 
and the excellence of Corinthian bronze had been rec- 
ognized long before that time. Moreover modern 
metallurgists know that no addition of gold and silver 
to any copper-tin alloy will cause it closely to resemble 
gold; and, though they do not know the exact composi- 
tion of the bronze of which several statues are said to 
have been cast, they believe that the same imagination 
that deduced that the beauty of the Corinthian bronze 
was derived from being cooled in the water of the 
fountain of Peirene also conferred upon the alloy the 
beauty that the Roman accounts praise. Was not the 
ancient praise simply the recognition of the qualities 
that cause us to cast our monuments in copper alloys? 

Copper-containing alloys are usually beautiful and 
always good and useful. They work their way through 
the world that we may dance to the tinkling of brass 
and pay our way in bronze and copper-gold. 


CHAPTER IX 
PUTTING COPPER AND BRASS TO WORK 


Copper has many lifetimes of work to do in the world 
when once it has been brought to’ the refined metallic 
state. Before it can enter into the active service of 
man it must be put through a series of rigorous shap- 
ings that will fit it for the different lines of usefulness 
that it willengagein. During this period it must meet 
other metals and arrange the permanent partnerships 
that are necessary in many cases. It must go through 
the treatments that will enable it to withstand the 
hardships of commercial life. 

Like most of us, copper does not have a chance to 
choose the particular kind of work it is to do. Only 
when its impurities bar it from the electrical field are 
its possibilities limited, and even then there are all 
sorts of interesting alloys it can help to form or many 
kinds of castings that it can fill. The destiny of a 
piece of copper begins to be shaped when it flows out 
of the refining furnace after electrolysis into a par- 
ticular form of mold and becomes wire bar, ingot, or 
eake. If it finds itself with the points of a wire bar 
it is able to feel rather sure that it will soon be a copper 
wire. If it is cast into a humpy ingot it can predict 
that it will become a copper casting, take up with zine 
and become brass, or possibly join with some other 


metal such as tin or aluminum. The copper in a cake 
213 


214 THE STORY OF COPPER 


is able to guess with great accuracy that it will find 
itself rolled out into a sheet or plate, eventually to 
appear on a roof or in a copper utensil. The chances 
are a little better than one to one that a particular: 
gob of copper will be a wire bar and a potential con- 
veyor of electricity. This is the proportion of copper 
cast in different forms in 1920, as given by the United 
States Geological Survey: 


Form Percentage 
Wire bars 52.53 
Ingots 27.42 
Cakes 12.80 
Cathodes 2.44 
Other forms 4.81 


It is rather difficult to say definitely how much cop- 
per is used in each class of fabricated material, and 
the estimates made are very approximate. But the 
copper marketed domestically in 1919 was apportioned 
roughly as follows: 


Use Pounds Percentage 

Electricity 500,000,000 47.8 
Brass fabrication 300,000,000 28.6 
Straight copper fabrication in 

mechanical goods 150,000,000 14.3 
Bronze, German silver, and other 

alloys 22,000,000 ye | 
Brass for remanufacture, mill cut- 

tings and shavings 75,000,000 7.2 


If the copper used by the world in one year were 
parceled out equally to every inhabitant of this earth, 
each person would have about 19 cents’ worth, 1.3 
pounds. The semi-savage on a tropical island would 
wonder what to do with all this metal, for he is famil- 
iar with it only in ornaments or the simplest sort of 


PUTTING COPPER TO WORK 215 


utensils. He would be content for a lifetime with 
only a few ounces. And, if such a distribution were 
made, there would be a serious and disastrous short- 
age of copper in America and Europe. The fact is, of 
course, that, although the average yearly per capita 
consumption of the world is 1.3 pounds, the bulk of the 
use is concentrated in the more advanced countries of 
the world. Going back before the de-civilizing World 
War, we find that the United States in 1912 used 7.7 
pounds of copper per capita, while the vast expanses 
of Africa, Australia, and Asia combined used only 
about eight thousandths of a pound per capita. Hur- 
ope used about 3.1 pounds per person, while the two 
Americas combined have the high record of 6.2 pounds. 

A truly wonderful statistical story is told when the 
consumption figures for the last quarter of a century 
are studied. Between 1897 and 1912 the world’s con- 
sumption of copper increased 139 per cent., and by 
continents the increase was: Europe, 105 per cent.; 
America, 218 per cent.; Australia, Asia, and Africa, 
233 per cent. Year after year before the War, the con- 
sumption of copper in the United States increased on 
the average of 13.5 per cent. a year. As is natural, 
these increases over sixteen years are largest in the 
undeveloped countries that were expanding at a great 
rate. If you are interested in the growth of copper 
use in the European countries during that period, here 
are the data: 


Country Percentage of Increase 
De Saree ee eke le ewe ese abe a hls 370 
Re ai sect op nen jniin'le winnie geen 182 
ES. a ed i a Ae Pa eared 163 
158 


Se tate tv Se os in els lele dw oie emis oles 


216 THE STORY OF COPPER 


Country Percentage of Increase 
Miscellaneous European countries .............. 150 
BY GHGS) sll ns hie wie a eto ete ease etre eee 94 
BREA yarns aug. Witwer Wy 2 iss Shae apma eer Saeko 44.5 


The rapid expansion of the mechanical age is the 
cause of this increase in the use of copper. Machinery 
is replacing human and animal muscle, metal is sub- 
stituting for wood, creations of the mind are soften- 
ing the callouses of the hands of men. And during 
the last twenty-five years more and more machinery 
has been electrically driven. Electrical expansion 
means copper expansion. 

Iron has been considered the symbolic material of 
the new mechanical epoch. We are told that we are 
in the Iron Age. But iron must share its glory with 
copper. Two steel rails will continue to carry the 
locomotive, but the steel will be paralleled by a strand 
of copper and the driving power will be electricity. 
The electrical era is partly here and coming fast; it 
is time to hyphenate the material first name of the 
era and call the present the ‘‘Iron-Copper Age.’’ The 
comparative consumptions of iron and copper trace 
this transition into the present age. From 1880 to 
1885 the world produced one ton of copper to every 
104 tons of iron. From 1901 to 1905 the ratio had 
dropped to 1 to 80, and it decreased uniformly until 
the outbreak of the war. For the year 1916, one ton 
of copper was produced for every fifty-three tons of 
iron, showing the greediness of war; more copper is 
required in modern warfare than in modern industry. 

Rapid as the increase in the use of copper has been, 
we must look forward to much greater demands in the 
future. In Asia about 900,000,000 people live who use 


PUTTING COPPER TO WORK 217 


only minute quantities of red metal. Modern inven- 
tions have not reached them; the principal Chinese use 
of copper is in their coins. If the Chinese should 
adopt modern inventions in the next twenty-five years 
to the extent that the Japanese have in the last quar- 
ter of a century their use of copper would add greatly 
to the world’s demand. If Asia reached the point 
where its per capita consumption was only one tenth 
that of the United States, its demands would exceed 
ours by about 130,000,000 pounds a year, and if its 
use should reach the figure for the present world aver- 
age consumption it would be consuming nearly 1,117,- 
000,000 pounds a year. Suppose that every country 
of the world used as much copper each year per person 
as the United States does at the present time. The 
total world’s requirement of copper would be enor- 
mous. Figure it out for yourself; the numerals are 
nearly too fantastic to write. 

There is a real difference between the amount of 
copper that a country consumes, the amount that it 
produces, and the amount that it manufactures. While 
the large consuming countries are also the large pro- 
ducers, they also manufacture the metal used by many 
of the smaller nations that have not yet reached the 
point of having their own copper and brass fabricat- 
ing industries. Just as some of the smaller countries 
send their youth to this country for training, so they 
may ship us their ore or their copper and receive in re- 
turn the same metal fully prepared and ready to go to 
work in their growing industries. Before the war 
Germany led the world in copper manufactured per 
capita with about 8.5 pounds, despite a lower per 


218 THE STORY OF COPPER 


capita consumption than America, and a very small 
per capita production. Most of the copper manufac- 
tured in Germany necessarily came from America. 
The United States was second in copper manufacture 
per person at the rate of about 8.1 pounds per year; 
the United Kingdom was third with about 6.7 pounds; 
and France was fourth with about 5.8 pounds. 

Turning these few pounds of copper per person, 
these millions of pounds of copper per year, into prod- 
ucts that go to the ends of the earth and penetrate into 
the heart of the home, is a large industry demanding 
many factories and many workmen. We have followed 
copper through its first stages of manufacture, in the 
mine, reduction-plant, and refinery; we can now see it 
turned into the standard kinds of wire, plate, sheet, 
pipes, and rods, both copper and brass, that are used 
in places to do their part in the work of the world. 

Every wire must first be a rod before it metamor- 
phoses into final form. The wire bar is the raw ma- 
terial used in the development of a copper wire. In 
the reduction of refined copper to wire or rod the 
processes used are principally physical, unlike those 
that separated copper from its ore. The wire bar is 
rolled into wire. 

A hundred wire bars are held on the table that feeds 
them regularly into a heating furnace, fired by fuel 
oil or other burners at the exit end of the furnace. A 
hundred bars enter and leave the furnace each hour 
under the urge of a compressed air pusher on the 
feeding end. The blushing bars, red-hot, proclaiming 
a temperature of about 750 to 800 degrees Centigrade, 
are picked up in tongs and carried to their first squeez- 


a 


PUTTING COPPER TO WORK 919 


ing experience. The first groove in the rolling-mill 
is called the ‘‘roughing mill,’’ and it is. Heavy steel 
rollers pick the copper up and do their best to squeeze 
out some of the wire bar’s fatness. When the first 
set of rollers has finished with it, the bar is dropped 
to a lower set of rolls which, after they have done their 
elongating, send it back to the other side of the ma- 
chine. Back and forth the glowing bar travels, and 
as it passes through about seven reducing rollers it 
gets thinner and thinner, lankier and lankier. From 
the roughing mill the bar passes to the intermediate 
-and finishing mills. In these it is rolled still more, 
and by this time it is so long and thin that it will not 
automatically pass itself from roll to roll but must be 
helped by a man who catches its end in a pair of tongs. 
When the wire bar has passed through the last roll 
and has finally become a rod, from one fourth to five 
eighths of an inch in diameter, it runs through an iron 
pipe to the coiling machine where it is wound on a reel. 
The finished coils are black with oxide formed while 
the hot metal was exposed to the air during the 
rolling process, and this is removed by ‘‘pickling’’ in 
a dilute solution of sulphuric acid. The coiled rods 
are then ready to be drawn into wire. 

The drawing of the rod into wire consists of pull- 
ing the cold rods through a series of dies of decreas- 
ing size and thus continuing the reduction of the 
diameter of the wire and increasing its length. For 
the larger size wires, the drawing is done through only 
one die at a time until it is finished, but with the smaller 
sizes the wire is taken at the same time through several 
dies grading downward in size. The wire drawing 


220 THE STORY OF COPPER 


machine has a series of drawing rollers, each of which 
pulls the wire through one die and passes it to the 
next. Each roller and the coil at the end of the proc- 
ess are geared so that they will take up the extra 
length of wire created by the drawing process. The 
rollers at the end of the drawing are speedier than 
those at the beginning. The small circular dies used 
for drawing are made of chilled cast-iron with a tap- 
ered hole. They are reamed to exact size by hand, 
and when the continual wear of the wire has made the 
hole larger by one thousandth of an inch, the usual 
variation of diameter allowed in all small wires, the 
die is reamed out to the next larger size and used 
again. A die will hold its size within this limit while 
about four miles of wire have been drawn through; 
then it must be given a larger opening. 

When wire bar was turned into rod the copper 
was hot and plastic; it did not change its hardness, 
ductility, or strength appreciably. But when it is 
drawn cold it becomes hardened, stresses are set up 
within it, and it loses its plability. The hardening 
occurs about in proportion to the reduction in diameter. 
This is quite satisfactory if hard wire is wanted, but 
if hardness is a disadvantage something must be done 
about it. To obtain soft wire, the hard copper is 
heated up until it just begins to get red, about 600 de- 
grees Centigrade, and then allowed to cool. The heat- 
ing relieves all the stresses and strains of the cold- 
drawn hard wire and leaves it untroubled, soft, and 
easy to bend. This process is called ‘‘annealing.’’ 
The properties of red metal put through this treat- 
ment, unlike those of steels and some copper alloys, 


PUTTING COPPER TO WORK __ 221 


do not seem to be affected one way or the other whether 
the cooling takes place quickly or slowly. 

Often a wire intermediate between hard and soft 
is desired, and this is manufactured by a novel method. 
As the amount of hardness varies with the work done 
on the wire in drawing, medium hard wire is produced 
by drawing the rod to a certain size which, after be- 
ing annealed, will require just the necessary amount 
of further drawing to produce both the § size and the 
degree of hardness specified. 

Copper wire can be drawn as fine as one thousandth 
of an inch in diameter, and a one-fourth-inch soft wire 
will stand a cold reduction to about one thirtieth of 
its sectional area in the dies. 

When trolley-wire, which must be furnished in long 
lengths, often a mile, is made, many rods must be 
joined together, and this is done by brazing the rods 
before drawing with solder of silver, the only metal 
that surpasses copper in electrical conductivity. Or- 
dinary round trolley-wire is drawn through cast-iron 
dies but for grooved, figure eight, and other shapes the 
dies are made of steel, carefully punched, sized, and 
hardened. 

In another process heated plastic metal is squirted 
into rods or wire. A hot billet is placed in a large 
machine and a great plunger, hydraulically operated, 
extrudes it through a die as easily as you squeeze out 
the allotted half-inch of tooth-paste every morning. 
This extrusion method is used for wire and rods of 
brass as well as for copper. This is the method used 
for the shaping of special forms, angles, T-bars, mold- 
ings, and other such designs, which are finished to di- 


222 THE STORY OF COPPER 


mension by one or two drawing operations. Many 
such special shapes are cut up and become machine 
parts and accessories. 

The cast cakes or slabs of copper that are destined 
to become sheet-copper go through about the same ex- 
periences as a wire bar. Hot rolling usually flattens 
the sheet partially down to size, and then it is finished 
down to size by rolling cold, with or without inter- 
mediate annealing depending upon the properties de- 
sired. 

At one time the making of sheet copper was the first- 
step in the manufacture of copper tubing. The vil- 
lage coppersmith took a hand- or machine-rolled sheet, 
shaped it around a core, and fashioned it into a seamed 
tube, secured either by the crimp or by rivets. Such 
slow and often unsatisfactory methods have now 
largely given place to modern machinery that will 
pierce and draw down a solid or hollow cast billet and 
make it into a tube, or that will extrude a copper tube 
through a die. Cylindrical solid billets from the re- 
finery that have been turned down on a lathe to re- 
move surface impurities and imperfections are used in 
the piercing, or Mannessmiann, process. After a bil- 
let is heated to about 850 degrees Centigrade, it is 
placed in the piercing mill where it encounters a 
steel point carried on a long rod. It is forced over 
this, rotating between the rolls that confine it and 
at the same time give it a powerful forward mo- 
tion. The billet is thus shaped into a thick walled tube 
as yet somewhat irregular in size. Its manufactur- 
ing experience is concluded in somewhat the same way 
as that of a wire. The pierced billet is sent to draw- 


PUTTING COPPER TO WORK 223 


benches and pulled through dies at the same time that 
its interior diameter is shaped and made regular by 
inside plugs or mandrels. The sizes of the die and 
plug are so proportioned that the outside of the tube 
is reduced in diameter more than the inside. The tube 
is made smaller and the walls are made thinner. 
Drawings and annealings are alternated as in the case 
of wire, and, when at last the shaping process is over, 
the tubes, tempered, cleaned, and straightened, are 
tested and sent out into commercial life. 

The piercing method of tube-making is rather 
strenuous. It is a hot-process method and can only 
be applied to those alloys or metals that can be readily 
shaped in that way when hot. Happily most of the 
brass tubing in use to-day is manufactured by this 
piercing method, which is the most economical. But 
for alloys that will stand cold-process treatment and 
will not stand the hot process, a method of tube- 
making known as the cast-shell method or sand-core 
process can be used. Instead of a solid billet, a hollow 
one is cast with a sand core that can be easily re- 
moved after solidification. The result is a seamless 
tube or shell that is drawn in exactly the same way as 
a pierced billet to form a finished seamless tube. 
When tubes of large diameter and thin wall are re- 
quired they are sometimes fashioned out of a disk or 
blank of sheet copper by piercing its center and then 
gradually shaping it. This blanking method is applied 
to metals and alloys that will not stand the hot pro- 
cess of manufacture, and it has the added advantage of 
allowing the blank to be inspected for surface condli- 
tions before it is shaped into tubes. 


224 THE STORY OF COPPER 


When tube manufacture is being described, do not 
think only of the round tubes that are used as con- 
denser-tubes or as pipes in our houses, but visualize 
also the odd shapes that are useful in the construc- 
tion of store-fronts, skylights, metal trim, and win- 
dow-sash. Brass and copper of special shape are 
fashioned by the drawing process in a manner similar 
to rods, wires, and tubes. 

One sort of seamed tube in appearance closely ap- 
proaches the seamless variety. If the edges of a tube 
shaped from sheet-metal are brazed together, the hard 
solder composed of copper and zine closes the seam 
so well that it becomes virtually invisible. Brazing, 
soldering, and riveting of copper have been favorite 
methods of joining two copper rods, wires, or sheets 
together, but welding, which makes more secure joints, 
is now in use by the three common methods. Copper 
may be welded by the ordinary smith-welding process, 
using borax or borax-mixture flux. The oxyacetylene 
blow-pipe, although it will not cut copper as readily 
as iron and steel because of copper’s capacity to con- 
duct away heat, will join two pieces of copper together 
in their own molten metal if a large pipe and lower- 
temperature flame are used. Any of the electrical — 
methods can be used, although in are welding two or 
three times the power is required for a copper weld 
than for iron. Electric welding is another case of 
copper aiding itself. There was once a time when all 
joints of copper wire were hard-soldered with brass 
and only roughly filed, not drawn. The wire that was 
joined in this way was made by shearing from rolled 
sheets of copper very narrow strips of nearly square 


PUTTING COPPER TO WORK 229 


wire, which was rounded by drawing through rough 
dies. This process was extremely unsatisfactory. be- 
cause of troublesome slivers that remained attached to 
the wire, and because of the bulkiness of the joints. 
When in the eighties early dynamos were being con- 
structed it was impossible to obtain suitable wire of 
considerable length because of these deficiencies in 
manufacture. Earlier Dr. Elihu Thomson had noted 
the possibilities of changing a high voltage current of 
moderate amperage to immense quantity of low volt- 
age, thus creating enough heat at the junction of two 
wires to fuse or weld them together. This scheme 
perfected is the Thomson method of resistance weld- 
ing. When this common operation of to-day was ap- 
plied to joining copper wire the welds were so secure 
that they could be forgotten and the wire could be 
drawn to perfection and the earlier defects eliminated. 
All copper welds are usually hammered in order to 
break up the cast structure and restore the strength 
and ductility of the welded portion. 

The most ancient of the processes for manufactur- 
ing copper is one that is practised only to a limited 
extent to-day. Primitive man hammered out his knife 
of red metal with a cudgel of stone; to-day, instead of 
slow and laborious shaping under the blows of the 
hammer, the rollers of the mill shape and squeeze 
copper into commercial articles. If a hammer is used, 
it is so large that one blow will punch out a finished 
product from a rolled copper sheet; only in art cen- 
ters and in the less advanced countries of the world is 
the crude method of shaping copper by a series of 
tiny indentations practised now. The other import- 


226 THE STORY OF COPPER 


ant method of shaping copper that was used by the 
ancients is in extensive use to-day. Although molds 
of stone have given way to those of steel and special 
molding sands have replaced haphazard earths, al- 
though advanced methods of keeping the copper pure 
and at the right pouring temperature have been 
evolved, casting is much the same procedure that it 
was four or five thousand years ago. 

Although copper is not flowed into its final state as 
often as the partnerships that it forms, castings of 
red metal find thousands of uses in this world. Fin- 
ished castings of copper are used in the making of 
electrical apparatus, and rough castings are often the 
first steps toward drawing pipe. Being cast is usu- 
ally not a new experience for copper. Virtually all 
copper at one time in its life undergoes the experience 
of running into a metal mold after 1t has been turned 
into blister copper or after it has passed through the 
electrolytic refining process. But most of the copper 
that flows into the form in which it is used in every- 
day life is poured into sand molds, usually damp, or, 
as the molder would say, ‘‘green.’’ Because of the ox- 
idation of the metal and the likelihood of the forma- 
tion of blow-holes owing to the giving off of absorbed 
gas during solidification, pure copper is more difficult 
to cast than its alloys. If a reverberatory furnace, 
such as was used in its refining, melts the copper, the 
poling process can be used to purify oxidized metal. 
But if a crucible is used care must be taken to prevent 
overoxidation, as manipulation of the copper is im- 
possible. Often a layer of charcoal or a handful of 
common salt is sprinkled upon the metal to form a bar- 


PUTTING COPPER TO WORK 227 


rier to the air. With good workmanship and care, 
successful copper casting can be obtained without the 
removal of oxygen that has found its way into the melt 
and combined with some of the copper. But modern 
practice favors the use of some substance, added to 
the molten copper before pouring, that will carry off 
this oxygen. Affinities of oxygen, such as phosphor- 
ous, silicon, calcium, boron suboxide or carbide, zine, 
titanium, and magnesium, not only remove this ele- 
ment but prevent the absorption of gases which would 

later cause trouble through blow-holes during solidi- 
- fication. Ideally, only enough of the deoxidizers are 
added to complete their job efficiently and then go off 
without a trace. Practically, as is often the case, this 
can not be done. Some of the added element stays 
with the cast copper and affects its properties. Most 
deoxidizers lower copper’s electrical conductivity, and 
this is a disadvantage, as many castings must serve 
as current carriers. Phosphor copper, containing 
about 15 per cent. phosphorous, is a common deoxi- 
dizer that is added to molten copper in the proportion 
of about 1 or 2 per cent., and, though phosphorous 
lowers electrical conductivity, it hardens the copper. 
Zine as a deoxidizer mimics phosphorous’s bad points, 
but silicon, introduced through the addition of silicon 
copper containing 10 per cent. silicon, does not affect 
either mechanical or electrical properties as markedly 
as phosphorous and zine. Silicon copper and boron 
carbide, another deoxidizer which gives excellent re- 
sults, can be added to excess without danger, as they 
will not remain in the copper but will go off with the 
dross that is formed on the top of the molten metal. 


228 THE STORY OF COPPER 


No matter how highly oxidized copper may be, and 
how unsatisfactory its tensile strength and ductility 
may be because of excess oxygen, several remelts with 
the use of a good deoxidizer will rejuvenate it and 
make it better than or equal to new metal. When cast 
copper, or, for that matter, any metal, is being dealt 
with, one unfailing characteristic must be reckoned 
upon. If you pour metal into a mold one foot long, 
you will obtain from it a casting only 1134 inches long. 
In passing from the molten to the solid state, the metal 
contracts 1.42 per cent., and this volume change must 
be allowed for by every one concerned with copper 
casting, from the designer to the machinist. 

It is true that some of the copper ingots remain cop- 
per even after their metamorphosis into other forms, 
such as castings, but many more of them once melted 
never see the pure copper state again. Most of them 
find themselves forced to associate with zine to form 
a very successful and useful combination, brass, and 
a large industry has grown up to care for this as- 
sociation. Smaller numbers of copper ingots form 
partnerships with tin, aluminum, nickel, gold and sil- 
ver, and other metals whose intimate secrets we have 
learned earlier. But the methods of forming metalli- 
ferous combinations are very similar. If we look into 
the details of arranging the partnership, brass, we 
shall have a fair general idea of the methods of manu- 
facture of the other alloys. 

In seniority, bronze outranks brass. So early did 
the combination copper and tin come into use that 
recorded progress of man had not yet begun. Brass 
is much more youthful, but even so it certainly dates 


PUTTING COPPER TO WORK 229 


before the Christian era. The brass partnership un- 
til only a little over a hundred years ago and less was 
brought about by the codperation of a compound of 
zinc with copper, not metallic zine itself. Calamine, a 
hydrous silicate of zine, and, perhaps, a zine carbon- 
ate, smithsonite, which is also occasionally called cala- 
mine, were the substances that were used as the source 
of the zine of early brasses. During the sixteenth 
and seventeenth centuries, metallic zine, probably 
known in the Far East before Europe had isolated it, 
was imported into Western Europe under various 
names: tuteneque, tuttanego, calaeém, and spiauter. 
From the last term the commercial name of metallic 
zine, spelter, has descended. 

There was no particular reason in the days of me 
production why brass should be made from spelter 
rather than calamine. There were indeed economic 
arguments in favor of the survival of the admittedly 
inexact, yet successful, calamine brass. And it did 
persist in commerical practice long after the first brass 
was made in America. If the substitution of metallic 
zine for calamine is excepted, there is little difference 
in the fundamentals of brass-making to-day and several 
hundred years ago. Proportions have been standard- 
ized, machinery has been perfected, production meth- 
ods have been made more efficient; that is about all. 

In 1645, Joseph Jenks, a native of Hammersmith, 
near London, came to Massachusetts as principal 
workman and machinist for John Winthrop, Jr. He 
is believed to be the first founder of the white race 
who worked in copper and iron on the western hemi- 
sphere. Three years later copper deposits were dis- 


230 THE STORY OF COPPER 


covered, and Governor Endicott brought smelters and 
refiners from Sweden and Germany. During the fifty 
years following 1725, Casper Wistar and his associates 
hammered out stills and kettles from brass and cop- 
per in Philadelphia, and they also manufactured and 
molded brass. And before the Revolutionary War it 
is certain that brass cannons were cast in America’s 
first capital city. Brass buttons were the first prod- 
ucts of the American brass industry which has arisen 
in New England. The people of Naugatuck Valley 
were making pewter buttons when superior brass but- 
tons came into vogue. They were forced to manu- 
facture the new buttons or lose their trade. Power, 
labor, and the other necessities of brass mills were 
present there, and this combination of conditions 
caused the industry to flourish, so that even now Con- 
necticut is the largest producer of brass in this coun- 
try. Silas and Samuel Grilley established a brass but- 
ton business at Waterbury, Connecticut, in 1802 and 
twelve years later Silas joined Abel and Levi Porter 
from Southington and Daniel Clark in making buttons 
from sheet-brass. This partnership through uninter- 
rupted growth and development grew into the Scovill 
Manufacturing Company of to-day. In fact, the brass 
industry can point to three great American companies 
that are over a hundred years old, a record equaled by 
few industries in America. The brass industry of 
this country in its initial stages was imported from 
England as was most of early New England. It was 
not until the Porters came to America that brass- 
making by direct fusion of copper and zine, according 
to the English process then only twenty years old, was 


PUTTING COPPER TO WORK 231 


introduced, and brass was rolled for the first time. 
Brazed gas-pipe made of brass was used in New York 
in 1836. Methods of manufacture improved continu- 
ally, but it was not until after American copper from 
Michigan had become available that American brass- 
makers took the lead over their English rivals, whom 
they have outdistanced ever since. 

Materially the fundamentals of a brass casting shop 
consist of the furnaces, crucibles, and molds. In the 
ordinary founding of brass mills of to-day, those that 
have not yet adopted electric furnace methods, a caster 
of three hundred years ago might easily recognize the 
basic equipment if he were brought to this age. A 
natural draft furnace is used, and our seventeenth cen- 
tury visitor would note the fact that anthracite coal 
or coke is used as fuel instead of charcoal or wood as 
in his time. Only one crucible is heated in each modern 
furnace, while the older practice was to place as many 
as eight in the same furnace. No doubt the intruder 
from the past would approve of the chimney that 
earries off the smoke of the furnace; he would re- 
member his furnaces that belched the smoke unpleas- 
antly into his casting-room. Crucibles now hold from. 
150 to 300 pounds of metal, and their usual life is from 
twenty-five to thirty-five heats, depending upon how 
well they are treated during firing and pouring. 
These containers of the molten metals, made of clay 
and graphite, represent an improvement over the cru- 
cibles of many years ago because the older ones were 
not made with the graphite, which greatly increases 
durability. Instead of the stone of older days, modern 
molds for brass are gray cast-iron. Sketches of the 


232 THE STORY OF COPPER 


old stone molds and those of a modern shop placed 
side by side would show a remarkable similarity in the 
way in which they are fastened together and the slant 
that is given them, but modern brass cast in flat bars 
or cylindrical billets finds itself put to many more uses 
than the older metal despite the similarity of their 
molds. 

The head caster of the brass shop of the usual type - 
is boss of process as well as labor. The whole produc- 
tion, from lighting of the coal fires to the cooling of the — 
cast metal, is in his charge. Controlling the fires, 
charging the crucibles, stirring and skimming the 
metal, preparing and pouring the molds are under his 
direction or actually done by him. 

About a dozen furnaces are fired at one time under 
his direction. The crucibles must be warmed care- 
fully before they are charged with metal so that they 
will dry out without flaking off or cracking. After the 
charge of copper ingots or copper scrap is placed in 
the crucibles so that it will melt without harm to them, 
a handful of common salt is thrown over the partly 
melted metal and stirred in to prevent oxidization and 
remove the oxide that has been formed in the metal. 
When the copper has melted and reached the proper 
temperature according to the judgment of the caster, 
the spelter is added. As zine is lighter than copper 
it will float on top of the molten metal, but if it is al- 
lowed to do this it will take up with oxygen of the air 
in chemical bondage and thus be lost to the molten 
brass. ‘To prevent this and to preserve the brass, the 
caster stirs the zinc into the copper thoroughly and 
covers the molten metal with a layer of charcoal or 


PUTTING COPPER TO WORK 233 


some other material that will act as both flux and a 
protection from the acquisitive oxygen. Then the cas- 
ter must be alert and be ready to pour the metal at ex- 
actly the right time; the metal must be sufficiently 
hot, but if it is allowed to heat too much a large amount 
of the zine will escape. His sense of touch tells the 
caster when the melt is ready to cast; the boiling zinc 
sends a peculiar vibration through his stirring-rod. 
A block and tackle attached to a light jib-crane is used 
to lift out of the furnace the crucible seized in a pair 
of tongs. Then the caster has the disagreeable task 
of skimming off the dross. To remove these impuri- 
ties he must stand in a white cloud of escaping zine 
oxide that pours off because of the removal of the 
protecting charcoal. He necessarily breathes some of 
this zine compound, and after such continual exposures 
he often suffers from ‘‘spelter shakes,’’ a form of 
poisoning. As soon as possible after the skimming, 
molds are poured. This is an operation requiring 
skill, and there are many chances of producing in- 
ferior castings. The making of brass by these 
methods has never been reduced to a science; the cast- 
ers go through the school of experience as apprentices 
and learn the secret and the knack of successful brass 
making and casting. Often through the use of these 
inexact methods there are greater variations in the 
composition of brasses turned out by a casting-shop 
than the manufacturers are usually willing to admit. 
A large amount of the variation arises through the 
volatilization of the zine. 

Oil-fired furnaces, now in use by some foundries, 
represent a decided improvement over those heated by 


234 THE STORY OF COPPER 


coal, since through the use of liquid fuel a better con- 
trol of heat is possible. Ashes and dirt are elimin- 
ated with a consequent refinement of the process. The 
oil-fired furnaces depart from the arrangement of me- 
dieval casting-shops, and the new method of heating al- 
lows larger furnace units to be operated. Oil firing 
also led to the introduction of mechanical handling of 
the crucible, so that a considerably heavier tonnage of 
metal can be melted at one time. 

Many brass manufacturers now use the electric fur- 
nace for melting and alloying copper and its junior 
partners. The heat that flows along copper wires, 
cold until it is needed, can be accurately controlled in 
intensity and distribution; electricity will stir the 
metal more thoroughly than human energy; and heat- 
ing by electricity can be accomplished without loss of 
metal or contamination by burned fuel or the air. 

For brass a furnace is used in which the molten 
metal heats itself because of its resistance to the flow 
of the current. As it heats itself the metal can also 
be made to stir itself and distribute the heat if the 
furnace is constructed to bring about this effect. Elec- 
tricity can also be made to replace the skill of the 
experienced boss of the crucible foundry in telling 
whether the copper is hot enough to stand the addition 
of the spelter, and whether the brass is of the proper 
temperature to pour into the molds. Automatic 
records of the temperature are taken by electric ther- 
mocouples whose sensitive parts consist of two wires 
of different metals joined together inside the furnace. 
The furnace-chamber is kept entirely closed during 
the operation, except when the furnace is being charged 


PUTTING COPPER TO WORK 235 


or skimmed, and there is little opportunity for impuri- 
ties to enter. Despite the better conditions of the 
electric furnace, it is general practice to sprinkle pro- 
tective charcoal on the top of the molten metal just 
as was done in the crucible process. Pouring of the 
molds is accomplished by tilting the electric furnace, 
whose spout and automatic tilting device discount the 
skill of the operator. 

Brass is perhaps the most difficult of the copper 
alloys to make on account of the likelihood of the zinc 
volatilizing. Bronze and the other partnerships that 
copper helps to form, though easier to concoct, are 
made in an electrical furnace usually of a type differ- 
ent from that used for brass. A revolving furnace 
heated by an electric are that is not in contact with 
metal is often used for bronze. 

Now that you have been told the story of how brass 
is made, you also know the history of the formation 
of the other partnerships that copper enters into. All 
of them pass through about the same experience as 
brass. 

Brass, bronze, and the other alloys are not always 
destined to become sheets, rods, wires, or tubes but 
often emerge from the foundry in their final form as 
castings of machine parts and in other cast shapes. 
When this is the case, instead of the billets and bars, 
the final shapes are poured directly from the crucibles 
or furnaces, using sand-molds similar to those in which 
copper is cast. But, if bars and billets are made, they 
are rolled and drawn through the same experiences 
that their copper prototypes pass through and finally 
emerge as sheets, rods, wires, or tubes. 


236 THE STORY OF COPPHR 


Some of the every-day things we see around us wear 
coats of copper. Sad to say, deception is the mo- 
tive of some of the baser metals donning red metallic 
coverings; in other cases a film of copper preserves an 
artistic or mechanical shape or reproduces it with 
fidelity, and at times copper is the underclothing of 
other metals, as it were. Coats of copper are applied 
by electrolysis. And electroplating is not the first ap- 
plication of electrodeposition that has been useful to 
copper, if you remember. When the copper passes 
through the great electrolytic refineries it goes through 
a similar change from metallic copper to solution, 
and then back again to metallic copper deposited as 
a solid. Then, if you remember, when tin cans are 
thrown in copper sulphate laden mine-water, and their 
iron is exchanged for the water’s copper, essentially 
the same sort of deposition occurs, although in this 
case an outside source of electricity is not needed, as 
the action is self-contained. 

Of all the metals, copper is the most easily deposited, 
and this is fortunate as it is the most useful after 
it is spread out in a film over another metal or sub- 
stance. The simplest method of creating a copper 
coat, perhaps, is to stick your knife-blade into a solu- 
tion of copper sulphate. It will come out with a red- 
dish film of pure copper. But while this is a simple, 
easy method it is not the best; the film does not stick 
and easily rubs off. In practice electroplating is ac- 
complished by placing the objects to be coated in a 
vat containing a solution of some copper compound. 
An incoming current passes through plates of copper 
also immersed in the vat and carries with it some 


PUTTING COPPER TO WORK 237 


of the copper into the solution, and then takes copper 
from the liquid and spreads it over the object to be 
coated. The solid copper that is being used is at- 
tached to what is called the positive pole or the anode, 
while the object being plated is the negative pole or 
the cathode. This does not sound complex and it is 
not, except that in practice close attention must be paid 
to the rate at which the current flows and the regularity 
of the deposit. The electrolyte must usually be kept 
in constant motion so that the deposition is of the same 
thickness in all places. If all the conditions of de- 
position are not just right, the metal is likely to de- 
posit in a powdery non-adhering form. If the current 
is too strong, ‘‘burnt’’ deposits, discolored and useless 
are produced. Large objects being coated are usually 
suspended in the tanks by hooks or wires, and they 
have to be moved constantly to be fully coated; and 
small articles are often heaped together with the cath- 
ode buried among them. 

The solution from which the copper is deposited, 
the electrolyte, may be various salts of copper, the 
sulphate, chloride, acetate, or cyanide. Hlectrodeposi- 
tion on its largest scale, that of copper refining, utilizes 
the sulphate, as you remember. Copper sulphate is 
also the common electrolyte used in copper deposition 
when no other metals are concerned. But the cyanide 
is used when the plating is done on or in the presence 
of the other metals. The reason for this is that iron 
-and zine, two metals that are often plated with copper, 
are unstable when in contact with copper sulphate or 
with the sulphuric acid that is always present in the 
copper sulphate electrolyte. They have a tendency to 


238 THE STORY OF COPPER 


give way to the copper just as the tin cans do, and the 
films formed are non-adherent. Copper cyanide, 
doubly poisonous though it is, is the only common com- 
pound of copper that does not harm these two metals. 

In practice a double cyanide of copper and potas- 
sium is used as the electrolyte; for the cupric cyanide 
is insoluble in water, while it will dissolve in a solution 
of potassium cyanide that is easily made with water. 
This solution is inferior to the sulphate in conductiv- 
ity, but its current carrying capacity is usually in- 
creased by heating. 

There is hardly anything that can not be given a 
coat of copper, electrically applied. Wood, wax, 
cloth, rubber, clay, plaster, leaves, flowers can all be 
preserved by red metal protection. And this can be 
done despite the fact that such substances do not 
themselves conduct the necessary electricity. This 
lack is remedied by giving the poor conductors a black 
coat of powdered graphite that allows the current to 
flow. But the creation of novelties or practical objects 
with a base of such materials is not so important as 
the deposition of copper on other metals. Sometimes 
a copper coat is valued for itself alone, but at other 
times it is a stepping metal to the deposition of some 
other metal. Copper is a very electronegative metal; 
this means that it is relatively easy to deposit upon a 
more positive metal, and the reverse is also true. 
When it is desired to coat one metal with another that 
is very close to it in the electromotive series, it is often 
found economical first to coat the base metal with a 
film of copper and then deposit upon this red coat the 
other more positive metal. Nickel-plating is often 


PUTTING COPPER TO WORK 239 


done over such copper underclothes. A lone copper 
film is valued because of its ability to protect more 
delicate metals from rack and ruin; a coat of copper 
properly put on substitutes for solid metal very well 
for a short while, as long as it is intact. 

Copper is manufactured electrolytically in some 
cases, although many more such processes have been 
worked out in the past than are used to-day. Seam- 
less tubes are made by depositing a thick film of cop- 
per on a rotating cylinder that can be withdrawn, and 
often very large tubes weighing up to five tons, which 
are difficult to draw, are made in this manner. This 
is also the first step in a method of making copper 
sheets; a cylinder of copper is deposited then slit 
lengthwise and flattened out. One method of produc- 
ing wire, which cannot, however, compete with rolling 
and drawing, is to deposit the metal on a cylinder as 
a strip which is then drawn down to size in the usual 
way. 

A copper film is useful because of its fidelity in du- 
plicating shapes. The little copper molecules snug- 
ele up to the material on which they are electrically 
placed and so faithfully reproduce it that it is some- 
times hard to distinguish between copy and original. 
Type and engravings made in soft type-metal or zine, 
which if actually used would wear away in little time, 
are given hard surfaces by electrotyping. In some 
cases, the type or engraving is made dirty with a light 
coat of grease, and a film of copper is deposited on 
its surface. This reversed plate is stripped off and 
used as cathode in its turn, and the result is that the 
finest lines of the original are accurately reproduced. 


240 THE STORY OF COPPER 


Another, and the usual method, is to make a wax im- 
print of the plate or type and to use its contact sur- 
face, graphitized, to deposit the copper of the new 
plate upon. By the same methods all sorts of objects 
of many different materials can be faithfully copied. 
Medals, statues, other works of art, wood blocks, ob- 
jets d’art, can be counterfeited with the aid of cop- 
per coats. Hollow copper objects can be made by 
molding a core of fusible metal, electroplating it with 
copper, and then making it so hot for the metal that 
it runs out and is ready for use again. 

Occasions arise when the material to be coated can- 
not come to the electroplating vat, and the vat must 
go toit. The barnacles that clutter up and hinder the 
hulls of ocean-going ships do not like copper and will | 
not attach themselves to it. Sailing-ships of several 
generations ago were sheathed with copper, and, 
though modern ships are made of iron, copper: barn- 
acle protection is still desirable. Electroplating vats 
are constructed with the, ship’s hull as both side and 
cathode, and in this way hulls are copper-plated. An- 
other method of coating large exterior surfaces is to 
‘paint them with a brush constantly wetted with the 
electrolyte and concealing a wire anode buried among 
its hairs or bristles. 

Coats of brass, bronze, and other alae of copper 
can be similarly applied to objects, but each alloy 
has its idiosynerasy. Brass cannot be successfully 
deposited from the sulphate solution for the same rea- 
son that copper and zine can be sucessfully separated 
from each other during the electrolytic purification 
of copper. From a sulphate solution the copper is 


SC TIOW ‘sary [eoo Aq pojeoy [ejow oy} Burssjs oie Wout yf, 
OLNI WOVNANA OIWLOWIA WOW SSvad ONINNOd dOHS DNI 


“LSVO SSVad NYYGOW V NI SHOVNUNA Lid 
‘OD sseig yodespiig jo Asayinog 


Courtesy of Bridgeport Brass Co. 


THE MACHINE THAT EXTRUDES PLASTIC BRASS LIKE SO MUCH 
MACARONI 


Rods squirted out by this extrusion machine are either drawn to shape and 
straightened for shipment, or they are drawn into wire. 


PUTTING COPPER TO WORK 241 


deposited while the zine is left in solution. Thus 
a cyanide solution must be used fundamentally for the 
same reason that this salt must be used for depositing 
copper. Even when a copper-zinc-potassium cyanide 
solution is used, more zinc must be placed in it than is 
desired in the brass because the zine is still much more 
backward about depositing than the copper. Simul- 
taneous electrodeposition of copper and zine in the 
form of brass has been suggested as a method of al- 
loying these metals to make brass, and, although it can 
be done, furnace methods are more economical. For 
electroplating with bronze, another salt is used, a com- 
bination of copper, tin, and ammonium oxalates. Ger- 
man silver, the alloy of nickel, copper, and zinc, is 
deposited from a cyanide solution. 

Though copper does not rust away like iron, it 
does lose its brilliant red color when it is exposed to 
the air. There forms a coat of tarnish—or oxide, to 
use a pleasanter and more correct term. In many 
cases this skin-deep coat that comes through service, 
like the sunburn on a sailor, enhances copper’s beauty 
and makes it more desirable from an artistic point of 
view. This becoming tarnish is often acquired natu- 
rally, but as often an even coat is applied artificially. 
Copper heated to a high temperature takes on a black. 
dull finish. A variety of other effects can be pro- 
duced on copper by various processes. Time and 
weather form patina, as the green carbonate of copper 
is colloquially called; not only can chemicals form the 
true verdigris, copper acetate, but time can be dis- 
pensed with and the effect of age can be produced 
overnight. Bronze and brass have the same ability 


242 THE STORY OF COPPER 


to look artistic when tarnished, because of the copper 
in their make-up, but the tin alloy wears its film of 
impurities most artistically. The truth of the matter 
is that brass appears best when highly polished, and 
the constant use of energy and polish necessary to 
keep it shiny is one reason why in these days of high 
labor costs it is not usually used purely as an orna- 
ment. Shiny brass, as well as polished copper, can be 
preserved without undue work and trouble if a trans- 
parent lacquer or varnish is spread over it as a pro- 
tection to the surface. 

Whither go these millions of pounds of copper that 
are fabricated each year? JEarlier in this story, a - 
table giving the approximate distribution of the copper 
used in each class of fabricated material was given. 
Estimates of the distribution of the copper consumed 
in the United States according to its ultimate uses have 
been made. During 1919, 1920, and 1921 the annual 
consumption figures were approximately as follows: 


Millions 

of pounds Per cent. 
Hlectrical manufactures |. .5 3.) 2.40 <5 seer 295 30.1 
Wire and rods not otherwise included ...... 153 15.6 
Telephones and telegraphs ............5008s 85 8.7 
AN TONIOHLLE i/o Baio acetate yee 3 atere eee 82 8.4 
ROPE Pa hs Sais ik seat onere sere le ce tet te ae cee 71 1.2 
Bearings and bushings... 0.4 2.5 +o. wenden 62 6.3 
Buatidin 96 ye ces lafnce'« 9 sale eon aon eae pene 60 6.1 
Machine: fittings -.0- 3) 6.2.2 .siie- ele 27 12.8 
Rallways. (wise cus siste sine @ 0 wus e bye eee 26 2.6 
AMMUNITION fase Die cs aisle adie oe esis 21 2.1 
CSGTTIS HA poo nih Maen iw lotca She Ve) cisad ou oto ee ne ‘pict etecotemees 3 2 
Fire-extinguishers 3) 059). ses bp © ects ies oe eee 2 = 
Pine ehb sala oy ete ns ates aie he oes an sae 2 2 
CASN-TEPLBLELE $1.5 o delete ae visteue vents eee 1 + 
Miscellaneous ::. Ji. .0..0 os ab os «5 sue odes cee 91 9.3 


Dota lid es aires eisae elena ale estan ae 981 100.0 


PUTTING COPPER TO WORK 243 


The diversity of the places in which copper does 
its work compares favorably with any other common 
- commodity upon which the world is dependent. And 
the way in which copper enters into the heart of our 
national and personal lives is an interesting story. 


CHAPTER X 
THE METALLIC SERVANT OF ELECTRICITY 


Suppose some fine winter morning the world should 
awake, yawn and stretch, and then discover that all the 
electrically-traveled copper in the world had been 
changed to sealing-wax. It would not take long to 
make the discovery. What a howl of discontent would 
be raised to the heavens! No light would beam forth 
with the punch of a button. There would be no water, 
hot or cold, for shaving. The electric cars would stand 
still on the tracks, and even the automobile would 
refuse to spark its gasolene through sealing-wax wires 
instead of copper. The telephone would not func- 
tion. Radio and telegraph would be useless; each 
small community would be totally isolated from the 
rest of the world. And a thousand other things would 
be radically wrong with the world. To be sure, there 
is little likelihood of such an Alice-in-Wonderland 
transformation happening. But just suppose. It 
would be a terrible hardship for our civilization to 
revert to the conditions of fifty years ago, before the 
extensive use of electricity began. We need and use 
electricity’s metallic servant, red metal, more than we 
know. The prehistoric barbarian with the first chunk 
of copper could not have realized the electrical use of 
the new material; even Ben Franklin’s sagacity failed 


him and he could not have even a glimpse of the future 
244 


SERVANT OF ELECTRICITY 245 


power that artificial lightning, copper-carried, has 
achieved. And probably the most theoretical and im- 
aginative electrical engineer and physicist cannot tell 
just where the copper-electrical age will end. 

Less than a century ago Faraday conducted his bril- 
hant researches into the nature of electricity that 
laid the foundation of its modern applications. It was 
an epoch-opening day when Michael Faraday, son of 
a blacksmith, spun a circular copper plate between the 
poles of a powerful magnet in the laboratories of the 
Royal Institution of Great Britain and thus operated 
the prototype of our immense current-producing 
dynamos of to-day. But it was not until the eighties 
of the last century that the great mass of electrical re- 
search began to give returns that impressed tle com- 
monplace mind. ‘hen the Edison electric light blazed 
forth, copper-carried current replaced horses as the 
pulling power for street cars, and men could actually 
talk over copper. People began to appreciate copper 
wires and what they could conduct. The production 
of this metal naturally felt the impulse of a new use, 
and red metal entered into its second growth. Only 
at this late date does it seem perfectly natural to think 
of a small copper wire transmitting power that can 
be changed into mechanical motion or light or heat 
at will, just as a pipe carries water. 

There are only three practical methods of sending 
energy from place to place: by mechanical means con- 
sisting of a shaft or a belt and pulleys; by compressed 
liquid or gas, such as water or air forced through 
pipes; and by electricity flowing through wires. 
Can you conceive of pulleys, belts, and shafting so 


BO Ns THE STORY OF COPPER 


flexible and efficient, and pipes so strong and tight, that 
they would carry the power equivalent to that carried 
as a routine matter by every trolley-wire and house 
feeder? By its aptitude for power-carrying, copper is 
taking the waterfall to the heart of the city; one in- 
stant tons of water drop; the next, tons of machinery 
hum. The quantities and potentials are much more 
immense than in the early days when a few volts suf- 
ficed. ‘The public was recently thrilled by the news 
that a million volts of electrical current had been 
transmitted and made to jump with a great nine-foot 
silky are from two copper contacts. On the Pacific 
Coast 10,000,000 pounds of copper are being used in 
the construction of the highest voltage transmission- 
line of the world, conveying current at a potential of 
220,000 volts. 

As the servant of electricity, copper is siete 
in efficiency by only one metal, silver, which will not 
hire itself out at a low enough price to compete. Even 
so, silver is only 6.2 per cent. more efficient than cop- 
per. The closest rival of copper is aluminum, which 
conducts with 60.5 per cent. of copper’s ability but 
has never stayed in real competition for copper’s job. 
Gold, with 71.8 per cent. of the conductivity of copper, 
cannot, because of its high price and lack of efficiency, 
compete in electrical matters. The hight metal, mag- 
nesium, is put out of the electrical conducting con- 
test on two counts, its 35.8 per cent. conductivity and 
the likelihood that it would act like a flashight powder 
on the first mild but heating overload unless the wires 
were laid in a vacuum. Zinc is low in conductivity, 
having only 27.2 per cent. of copper’s record, but was 


SERVANT OF ELECTRICITY 247 


used electrically in Germany when war needs caused 
a severe copper shortage. Since the war and upon 
the resumption of copper imports, Germany has abso- 
Iutely ceased using zine in electrical apparatus; such 
material is only exported. Iron also is a very poor 
conductor of electricity and is used only when high 
conductance is not a necessity or when copper cannot 
be had. 

Only one metal has ever threatened copper’s ab- 
solute supremacy as the servant of electricity. Alumi- 
num with less than two thirds the conductivity is at the 
same time very light; it weighs only a little more than 
one third as much. Thus an aluminum wire weighing 
only half as much per foot as a copper wire would 
conduct the same amount of current, although 1t would 
be two thirds greater in area. For ordinary wires, 
the bulk and cost: of aluminum have prevented its 
use, but for high-power transmission it has been 
looked upon with some favor, and at one time the 
transmission-lines running into Butte, Montana, the 
largest copper-mining camp in the world, were of 
white instead of red metal. They have since been re- 
placed with copper. Data show, however, that copper 
is mechanically much stronger than aluminum, that 
for eaual cross-section aluminum has but half the 
strength of copper, and for the same electrical con- 
ductivity the breaking-point of aluminum wire is about 
80 per cent. of that of copper wire. This means that 
if copper or aluminum is used on a power transmis-_ 
sion-line the aluminum wire would break with 80 per 
cent. of the strain required to break the copper wire, 
assuming that neither wire was the least bit scratched 


248 THE STORY OF COPPER 


or nicked. As aluminum is very soft, it is more liable 
to injury, and slight mechanical injuries which may 
readily happen in erecting or handling an aluminum 
wire reduce the mechanical strength of the wire 
greatly. It is possible that sudden breaking of alumi- 
num wires which occurs from time to time is due to 
such injuries suffered during erection. Aluminum’s 
lack of strength was compensated for by making the 
large aluminum cables with steel centers to take the 
load, but in hilly country it has been found that the 
outside layer of soft metal will not ‘‘stay put’’ and will 
creep down toward the low end of the line, slipping on 
the steel center and causing a bunching of loose alumi- 
num wire at low points. Though this drawback is still 
troublesome it has been overcome to some extent by 
using double clamps, one for the aluminum and one for 
the steel. An are, because of a short circuit or of 
wires momentarily swinging together, may cause seri- 
ous damage to an aluminum line on account of the 
low fusing point of that metal. An are on an alum- 
inum line usually burns and pits the wire, and as a re- 
sult reduces the mechanical strength. With a copper 
conductor, however, the arc has little or no effect, as 
the resulting heat is carried off and dissipated as 
easily as the current is conducted. 

The fact that aluminum of the same conductivity 
is considerably lighter than copper, the ratio being 
two to one, leads some engineers to think that lighter 
towers could be used. HEixperience shows that the 
reverse is the case, because it 1s not the dead-weight 
of the line that determines the necessary strength of 
the tower, but the strains in the towers and cables 


SERVANT OF ELECTRICITY 249 


because of winds. Aluminum has a cross-section 64 
per cent. larger than the equivalent copper wire, and 
therefore offers more resistance to the wind and hence 
causes a greater side pull. Under sleet conditions a 
greater area of sleet will collect on aluminum than on 
copper, and at such times there are generally high 
winds. Aluminum, on account of its greater coefficient 
of expansion and low tensile strength, requires higher 
towers; experience has shown they must be at least 
10 per cent. higher, or, if towers of the same size are 
used, they must be placed closer together, increasing 
not only the cost of the towers themselves, but also 
the cost of digging and installing tower footings and 
insulators and of stringing the wire. Under certain 
conditions, because of the greater sag of aluminum 
wire, wider right of way is required for the wire to 
sway in. Copper, being heavier and also having a 
smaller diameter, and being strung with greater ten- 
sion, will sway less than aluminum when the wind is 
blowing either at right angles or partly or wholly in 
the direction of the line. The cost of erection of an 
aluminum line is likely to be greater than with copper 
on account of the necessity of greater care and in- 
spection. Aluminum’s softness causes its wire strands 
gradually to wear in two at insulators, and sharp sand 
or dust in localities having sand and dust storms ag-— 
eravates this condition. It is also asserted that ex- 
tensive contact between galvanized steel and the softer 
metal invites corrosion especially where atmospheric 
conditions are unfavorable. Thus, while on paper 
there is sometimes a saving through the use of alumi- 
num conductors for high-tension current, in practice 


200 THE STORY OF COPPER 


it is generally found to be uneconomical, because of the 
much lower factor of safety. Copper is coming into 
its own again as the most desirable conductor for high- 
tension lines. Nearly a thousand miles of copper 
cable, which became the highest-pressure overhead 
line in the world, were recently shipped to California 
wound on 1928 reels, each containing half-a-mile of | 
conductor. It was the largest order ever placed 
for transmission cable, and the shipment required 
107 cars. This cable is built like a rope from seven 
wires of seven strands each, and each of the forty- 
nine wires is a little more than one tenth of an inch in 
diameter. The weight per mile of the cable is 8400 
pounds, and a new kind of threaded cast connector is 
being used for the first time on this lot of cable. 

Many transmission-lines, a large number operating 
on 110,000 volts, connect power sources with industries 
and cities. In the future many more miles, requiring 
many thousands of pounds of copper per mile, will 
be required. The electrical expansion of this coun- 
try is still in its infancy, although it has progressed at 
a greater rate here than in other parts of the world. 
Most of the power is now generated at steam or hydro- 
electric plants that supply one particular region alone; 
in the future we may expect to see high-tension lines 
covering the industrial parts of the country like a fish- 
net. All the available water falling wastefully to the 
sea will be put to work and transmuted into power to 
be fed into the general arteries of the red metal muscles 
of the nation. Steam-plants at the coal mines will 
economically turn past sunshine into present electrical 
power and thus use the coal more efficiently than in 


SERVANT OF ELECTRICITY 251 


these days when it must be transported by steam rail- 
roads to its place of use. Instead of ribbons of steel, 
wires of copper will deliver the energy of the coal 
mined in the future. You will buy your coal from the 
power company by the meter-full and have it delivered 
by wire. On the cloudless deserts where billions of 
horse-power of solar energy rest unused, power-plants 
will be established connected to a copper outlet. And, 
when there is a national power net, we may expect to 
see the moon as well as the sun harnessed; the slow 
power of the tides will benefit man. From gas made 
of peat and lignite, sources not now extensively ex- 
ploited, power will be obtained to satisfy the increasing 
craving for energy. In Italy volcanic heat is used to 
create current for use in cities some distance away, 
and it is predicted that copper will do its share in tap- 
ping the inner energy of the earth for man’s use. 
Government engineers have already surveyed the 
first proposed ‘‘superpower’’ system that could ef- 
fectively net all of the North Atlantic industrial region 
from Boston to Washington for power purposes. In 
this zone in 1930, 31,000,000 kilowatt-hours will be re- 
quired, and the United States Geological Survey re- 
ports that this energy could be supplied by a coordi- | 
nated power system at an annual cost of $230,000,000 
less than by an uncoordinated system such as is now 
in use. There would be a saving of about 50,000,000 
tons of coal each year, an amount that posterity would 
appreciate. The total investment in generating and 
transmission facilities for the superpower system 
would be $1,109,564,000, of which $416,346,000 would 
be the value of existing equipment to be incorporated 


202 THE STORY OF COPPER 


in the new system. Of necessity, much copper would 
be used in making this expansion. The great Colorado 
River, serving and cutting the Southwestern States, 
is the power source out of which will arise an industrial 
West the equal of New England. Once state’s-rights 
are settled and the necessary development begun, 
many millions of pounds of copper will be required. 
As it is, an electrical journal estimates that during the 
next decade in eleven Western States electrical plants 
will be constructed with a capacity of 2,800,000 horse- 
‘power requiring 280,000,000 pounds of copper. 
Kurope and South America have large electrical pro- 
grams ahead of them, and some day, perhaps not very 
soon, Asia and Africa will be marked with lines of 
power. 

In addition to the many thousands of pounds in the 
transmission-cables, much more red metal is used in 
the generators, transformers, and motors that create, 
change, or use electricity. From immense generators 
that send out their product pitched at thousands of 
volts, the current travels over the copper cables until 
it nears its point of use. Then thousands of volts are 
stepped down by large machines to hundreds so that 
they can be used to feed our lights, run motors, and 
otherwise energize the world. Wherever electricity 
must flow in these machines, there copper must be to 
earry it along. 

One of the most promising applications of copper 
and electricity is to railroad transportation. If we 
had our railroads to rebuild, a steam locomotive would 
be a rarity. The possibilities of railroad electrifica- 
tion can be visualized from the following quotation 


SERVANT OF ELECTRICITY 253 


from the superpower survey report: ‘‘Within the 
Superpower zone there are 36,000 miles of railroad 
measured as single track—that is, including each track 
of main lines, yards, and sidings. Of this total about 
19,000 miles can be profitably electrified, so as to yield 
by 1930 an annual saving of $81,000,000 as compared 
with the cost of operation by steam. The capital ex- 
penditure necessary to electrify the 19,000 miles would 
be $570,000,000, and the average return upon the in- 
vestment would therefore be 14.2 per cent.”’ 

Hlectric trains have many advantages over those 
hauled by steam. They can get under way much 
faster, achieving the speed of thirty to forty miles an 
hour in about as many seconds. They are speedier; an 
electric locomotive holds the world’s record for rail- 
road speed, 131 miles an hour. ‘Trains can be run at 
closer intervals if the road is electrified, and the dirt 
and cinders of steam travel are absent. The engineers 
laying out an electric road can include grades that 
steam locomotives could not climb, as an electrical lo- 
comotive can call upon the energy of immense machines 
in distant power-houses to help it climb hills. Paral- 
leling the two steel rails of the ordinary railroad, the 
electrified line has an elevated wire of copper carry- 
ing the electrical energy so that it can be tapped at 
any point. A considerable mileage of railroad track 
has been converted to copper and electricity here in 
America and in Kurope. The American heavy-traction 
roads that have either changed over or begun to do so 
include portions of the New York Central; New York, 
New Haven, and Hartford; Norfolk and Western; 
West Jersey and Seashore; Pennsylvania; Chicago, 


254 THE STORY OF COPPER 


Milwaukee, and St. Paul; and Butte, Anaconda, and 
Pacific railroads. For each mile of electrified road 
from 8000 to 35,000 pounds of copper are used. In 
the superpower survey it was estimated that 13,500 
pounds of copper would be needed for contact wires 
alone on a double-track system. 

The street railways are also large consumers of 
copper in wires and equipment. The ordinary city 
electric car contains from 1000 to 2500 pounds of 
copper, and some of the larger interurban cars have 
nearly 4000 pounds. A ten-car subway train in New 
York contains about 30,000 pounds of copper. In- 
cluding the feeder system, overhead trolley, bonding, 
car equipment, and power-house contents of cop- 
per, the average city electric line uses from 15,000 
to 20,000 pounds of copper to the mile of track. As 
there are approximately 45,000 miles of electric rail- 
ways in this country, about 675,000,000 pounds of cop- 
per are used in the street railway business. The other 
modern forms of transportation are just as subserv- 
ient to copper and electricity as electric traction. No 
automobile or aéroplane could run without its ignition 
system, any more than an electric automobile could 
travel without its storage battery. 

More than half of the copper mined, smelted, refined, 
and manufactured in this country is used in the elec- 
trical industry. Industrial power is the field of great- 
est promise for the future of the combination of elec- 
tricity carried by copper, but whatever electricity 
touches must have copper. Even the electric fixtures © 
and fuses which do not actually carry current need cop- 
per as a component of their brass. Incandescent 


SERVANT OF ELECTRICITY 259 


lamps to the number of about 150,000,000 are manufac- 
tured each year, requiring 1,000,000 pounds of copper. 
We think of using electricity as a source of light prim- 
arily, but current would much rather turn itself into 
heat than light. In fact it does, as you can prove 
for yourself by putting your hand on an electric 
lamp. Current is an ideal heat-producer without 
flames, smoke or ashes, and the future will see our fur- 
naces made of resistance wire set conveniently in every 
room of the house. Copper-carried current is a very 
useful thing to have around the house. It will per- 
eolate the coffee, make tea in the samovar, warm the 
milk for baby day or night, cook cereal or milk, toast 
bread, fry eggs, cook food in a chafing-dish, pop corn, 
bake griddle-cakes and waffles, knead and bake bread, 
heat the flat-iron, the fireless cooker, or the electric 
range, warm water for shaving or the bath, sterilize 
water or utensils, curl and dry hair, light cigars, keep 
heating-pads hot to replace leaky hot-water bottles, 
heat the bath-room on a cold morning, thaw frozen 
brass water-pipes, wash dishes, polish the silver, op- 
erate the washing-machine and clothes-wringer, dry 
the wash and iron it, run the vacuum-cleaner, polish 
the floors, operate the sewing-machine, play the piano, 
massage the face, cool you with an electric fan, make 
ice, mix family beverages, illuminate the house, pro- 
tect the house from burglars, run the dumb-waiter, 
give electric treatment and electric baths, purify drink- 
ing-water, amuse the children with electric toys, and 
haul the family in an electric automobile. 

The nerves of the world are copper. More impor- 
tant than the red metal arteries that bring power are 


bo 


06 THE STORY OF COPPER 


the metallic wires that carry thought. The world has 
had its nerves, the telephone and the telegraph, much 
less than a century, but now it could not part with 
them and still live as it does. Radio is a recent addi- 
tion to the world’s nervous system, which has virtually 
annihilated the fourth dimension, time. 

By far the largest investment in a single raw mate- 
rial is the $100,000,000 that the Bell Telephone System. 
has tied up in the approximately 700,000,000 pounds 
of copper estimated as contained in its nation-wide 
system. In the other telephone plants and systems of 
this country, according to mileage figures, there seem 
to be in the neighborhood of 100,000,000 pounds more. 
In the telegraph lines of the Western Union and Postal 
Telegraph companies, there is probably an additional 
200,000,000 pounds of copper, and the miscellaneous 
independent telephone and telegraph lines operated 
by railroads and private companies are estimated to 
contain about 50,000,000 pounds of copper. In all the 
telephone and telegraph plants of this country there 
are therefore about 1,050,000,000 pounds of copper. It 
is said that the United States contains 60 per cent. of 
the total telephone and telegraph mileage of the world, 
and if this is correct the total amount of copper used 
in the world’s telephone and telegraph systems is about 
1,750,000,000 pounds. In the Bell system there are 
nearly 28,000,000 miles of copper wire, and there are 
about 34,000,000 miles in all the telephone systems of 
this country. Only a small portion of this is strung 
up on poles, single stranded, as telephone and tele- 
eraph wire is actually visualized. Eighty-six per cent. 
of the miles of Bell system nerves are in underground 


Courtesy of Amevican Telephone and Telegraph Co. 


COPPER NERVES 


The thousands of copper wires through which flow the electrical current carrying 
the voices of the city. View of the back of a telephone central station. 


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sq, ‘sezod uo Bunsajs soimm suoydels} [enprarpuy 


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“uOTJON.AIJsUOD S}I MOYS 0} paiedeid AyT[eIDadsa ‘1oyouIE 
“Ip ul sayour %z Ayuo s[qeo suoydejey jo asad W 


SHYIM WAHddOO 00r~ 


}00 pauury 
21989 4184 ddd). : 


SERVANT OF ELECTRICITY 207 


and aérial cables, sometimes as many as 1200 pairs of 
wires running along together under the same protec- 
tion. If all the copper wire that is used to-day were 
strung on the surface of the ground there would be 
little room for anything else in parts of our cities. 
Would you like to have the sensation of using 2,900,000 
pounds of copper? Go to New York and call up San 
Francisco on long distance. You will be telephoning 
over a transcontinental line of 3400 miles. 

As a new part of our daily life we have acquired 
radio. Compared with the voice-transmitting wire 
telephone and the correspondence-transmitting wire 
telegraph, the radio that talks and stutters broadcast 
through the ether is called wireless. ‘‘Wireless’’ ap- 
plied to a radio set is as much out of place as ‘‘horse- 
less carriage,’’ the name given to the first automobile. 
Copper wire is a necessity in the radio set just as it 
is in any other piece of electrical apparatus. There 
must be the antenne on the roof or in a coil to catch 
the ether vibrations, a lead-in wire of copper must 
bring them to the set, and then the coils and other parts 
of the apparatus must transform the radio-frequency 
current into one that will produce sound in the tele- 
phone receivers. The continuous circuit from roof to 
ears must of course be essentially copper, and, in ad- 
dition to this, brass contacts and trimmings are often 
used. In many cases the detector that translates the 
radio waves into electric vibrations audible in the re- 
ceivers is a selected crystal of chalcopyrite, the impor- 
tant copper ore. Contrary to the first thoughtless 
conclusion, radio will not cause a decrease in the con- 
sumption of copper for the nerves of the world. Re- 


00 6. THE STORY OF COPPHR 


cent advances in telephone science have resulted in a 
dozen telephone calls and about half as many telegraph 
messages being sent over the same long-distance wire 
at the same time, and yet more copper is being used in 
building new telephone and telegraph facilities. The 
radio receiver fed by great government transmitting- 
stations may soon rival the telephone in the rural 
districts, which are now two fifths equipped with tele- 
phone service. Radio enters a new field; it will enable 
one man to address the world. It is to the telephone 
what the newspaper is to the letter. We may predict 
that a time will come when we shall be able to see by 
radio or wire. With these possibilities, the use of 
radio is predestined to exceed greatly the rosiest 
dreams of the radio apparatus makers created by the: 
broadcasting boom. With 1,000,000 to 2,000,000 radio 
sets in use, with each set using only five pounds of cop- 
per, this new addition to our national nerves is using 
from 5,000,000 to 10,000,000 pounds of copper. If this 
number is increased at the rate of only a million sets 
a year, a new and important use for copper has been 
developed. 

On a summer afternoon, when nature turns the sky 
into a leaking power-house and the thunder rolls, a 
copper lightning-rod is a handy thing to have on top of 
the house. Yet much has been learned since Franklin 
invented the single lightning-rod with a sharp point on 
it. It once was believed that lightning-rods afforded 
protection by dissipating the charge induced on a build- ° 
ing by a cloud, but this idea has been shown to be er- 
roneous. The electrical charges are so great and the 
connection of the lightning-rod with the ground is such 


SERVANT OF ELECTRICITY 209 


that the small dissipation of electricity possible 
through the sharp points of the rods can have no ap- 
preciable effect on the total charge. For this reason 
lightning-rods do not need to have sharp points, and 
for the same reason the rods cannot attract lightning. 
Nature hurls her electrical bolts hit or miss wherever 
she desires. They may strike a building or they may 
not, but the lightning-rod has little to do with it, say 
the meteorologists. The important thing is to have 
something there that will carry off the electricity from 
the clouds if it should select your house. Then any 
kind of lightning-rod, even one loose-jointed or badly 


- grounded, will be better than none, for it will provide 


an easier path to the ground than one through the 
building itself. Copper with its high conductivity is 
the best material for rods. 

South of the White House in Washington, the Wash- 
ington Monument rises high in the heavens, the easy 
mark for every passing thunder-storm. In 1885, when 
the monument was completed, an extensive lightning 
protection system was installed, made principally of 
copper. To-day it stands just as it was installed. 
Two hundred copper points, gold-plated and tipped 
with platinum, set on copper rods running along the 
base and edges of the pyramidion that caps the monu- 


ment, act as a cage, the best type of lightning protec- 
‘ tion. Larger copper rods lead to four iron columns 


that form part of the framework of the interior of the 
monument, and copper rods convey the lightning to the 
ground Aone the column ends. 

It is not necessary to gold-plate and platinum-tip 
your copper lightning-rods. In fact, the best sort of 


260 THE STORY OF COPPER 


protection against lightning as well as against the rain 
that accompanies it would be a copper roof, with cop- 
per down-sprouts, well grounded. In storm or fair 
weather, copper will prove itself a good conductor. 


CHAPTER XI 
BUILT OF COPPER 


As long as copper was in demand for weapons and 
was not plentiful, ancient man could hardly have used 
this metal for building material, despite his undoubted 
recognition of its superior properties. When iron and 
steel momentarily relieved copper of the burden of 
fighting wars, when methods of claiming copper from 
the earth had become improved, when the statues of 
bronze and copper and the copper household utensils 
had demonstrated copper’s usefulness, beauty, and 
durability, then the red metal began to be used in the 
construction of shelter. 

In early days copper was too sacred, too beautiful, 
and too hard to win from the earth to allow its use 
in the houses of the ordinary people. Cathedrals, 
temples, and public buildings were protected and 
ornamented through the use of copper. For example, 
acheologists have discovered that the Grecian treas- 
ury of Atreus at Mycene was lined with bronze plates. 
A thousand years and more later, when St. Mark’s 
Cathedral in Venice was rebuilt and beautified, it was 
roofed with thin sheets of copper. In many of the 
other cathedrals of Europe, copper or bronze was also 
used for massive doors and other parts of the edifice. 
On the other side of the world there will be found to- 


day, housing priests of different religions, temples 
261 


262 THE STORY OF COPPER 


capped with copper. For five centuries and more 
these same roofs, which promise long service still, have 
withstood the storms and the sunshine that their gods 
have bestowed upon them. China’s famous Temple of 
‘Heaven in Peking, as well as numerous Japanese 
temples, are roofed with copper, and at Kanakura in 
Japan there is a shrine built in the form of a colossal 
bronze Buddha thirty-six feet high, with eyes of gold. 
For 670 years this figure, said to be Japan’s greatest 
work of art, has breasted without injury tidal waves 
that swept away the great temples that sheltered it. 
It has only weathered to the permanently beautiful 
green patina. 

- The industrial and economic advancement that has 
made the lot of the ordinary worker of to-day easier 
and better has brought copper within reach of the 
builder of a modest home. As in the early days, cop- 
per continues to be used in sacred and public struc- 
tures, but they do not now monopolize this material. 
In our Eastern cities that have had the opportunity of 
acquiring a past, there are many buildings, far too 
numerous to enumerate, on which copper roofing has 
been used for at least seventy years. Some of the 
most famous structures in America’s history have been 
protected by copper. When Faneuil Hall in Boston 
was recently repaired copper roofing ninety-five years 
old was found to be ready for at least twenty-five 
years’ more service. Signers of the Declaration of 
Independence worshiped in Old Christ Church in 
Philadelphia, which has worn a copper roof for 173 
years, and this same roof, which was already three dec- 
ades old when our country was born, promises further 


BUILT OF COPPER 263 


satisfactory service. Trinity Church in New York, 
though now overtowered by copper-capped sky- 
scrapers, has a copper roof that was laid in 1846, and 
recently, when a new Fifth Avenue Baptist Church 
was being built, copper was the roofing material. In 
Wall Street a modern temple of finance is being built, 
' the new building of the New York Exchange, and 
copper is playing an important part. The highest 
point in New York’s forest of sky-scrapers is the huge 
copper-covered lantern on the peak of the Woolworth 
Building, and low down among these great buildings 
is the cupola of New York’s City Hal!, copper covered. 
Next to the National Capitol in Washington with the 
bronze Liberty on its dome stands one of America’s 
most beautiful buildings, the Library of Congress. 
Most striking is its gold dome, ‘‘22 carat fine,’’ as the 
guide-book will tell you; and contrasting pleasantly 
with this splendor is its roofing of verdigris copper. 
If the guide-book is closely studied it will be found that 
the flaming torch of Science and the golden dome are 
basically black copper supporting a heavy layer of 
very fine real gold gilt. Such are a few of the famous 
roofs of America. ‘To list more would be as futile as 
to include a directory of copper-roofed American 
homes built for the future as well as the present. 
Useful and ornamental as copper roofs are, they do 
not monopolize the structural use of copper. Even in 
the buildings that are not graced by a copper cap of 
pleasing green or brown, large quantities of copper 
and its alloys are often used in wires, pipes, flashings, 
cornices, screens, all forms of hardware, and many 
other building parts. The ordinary person who sel- 


264 THE STORY OF COPPER 


dom stops to think about or observe the buildings he 
inhabits daily does not often realize the extent to 
which copper and its alloys are used. 

Grand Central Terminal in New York is a large com- 
munity in itself, with stores and offices as well as all 
the equipment necessary to a large railroad station. 
Perhaps a mere listing of amounts of copper used 
for various purposes will prove illuminating. 


QUANTITY OF COPPER USED IN THE GRAND CENTRAL TERMINAL, NEW 
YorK CITY 
A Buildings. Includes main station building, Grand Central 


Terminal Building, post-office and office-building, service plant, 
Sub-stations Nos. 1 and 1-A: 


Pounds 
Roofs, flashings, ete. 2). '.:2.0%% sn stereo lars een 361,100 
Rxtended metal... fo dec. oils wo etre a 200,200 
Kealaminre ify be ai sik 5 Biss Sleds sonics ota naan 33,880 
Hardware. oi intense cle sadn +e supelelgs et oe 74,140 
Art Bronze Vii. aS elbaws Uy da Sa ee ae ee 139,260 
Grille vwork: 04 eins das eo ol es ee 4,790 
Wiring and panel-boards .. 0... vc selene eee 126,490 
Lighting fixtures (200/500 /0 5 20s sin bt 68,980 
Switch-boards  s.cc05 sc.cte.cis « a Se eis we ace eee 6,100 
Telephone equipment... 0004/40 5 «ne eee ee 5,900 
Self-winding clock equipment ............-.-e0+. 3,580 
Deslke-fans -) ..)4 c's eo Gk © © olece ee sony ie 1,000 
Hydraulic: elevators 1.00.05 2 asec sete Sa oaehat ate 3,260 
Electric clevators 00:44: 4 cosy ce ee ee 26,000 
Elevator door machinery , ....2....s-eensewoe 960 
Elevator signals 3). 02.2 f..«. 35). ae. te eee 2 3,000 
Baggage-room door machinery .......+..+++++ee- 170 
Window operating machinery. ............cseecee 200 
Ventilation rangers)... 4.0... oii... 4s pe 2,630 
Motors 3.5 ..'c.1. 6 cbse ca cas be, 0b noel teen 19,930 
Pump impellers. \.0....0. 04.0.9) 2 ae 200 
Plumbing fixtures 3.. ...3...5. «2 Gee ee 3,970 
Valves. ee ilies ow so wiele seus urs ole Blanes een 10,850 
Tubular ‘water-heaters (i002. 5.0.05 )s sero eee 1,000 
Meters, including brass piping ............-..--- 2,130 
Recording thermometers ..........++++sseseeeees 330 
Fire-hoge accessories. oo. ss .es/e0 6 oo weiner 2,410 
Tire-extinguishersS ......e+scecsecereseercersers 3,800 
Refrigerator equipment .........-. sere eee eene 290 
Laundry equipment ........ceeee esses eeeceeres 500 


Ducts and sheet-metal 7... 2... swe eee 2,250 


BUILT OF COPPER 265 


Pounds 

ere es ss ies hubba he ba wlebaa bee 10,900 
eee EER yc yw'n sae ga silt Cees acs eens te 6,040 
Pree tara te et). ENE ek ka bee wees 620 
SOEs I MBOA TURE bye ep be deeb lao bbws 360 
Lunch-counter and boot-black fixtures .......... 3,170 
Pee UMINPCQULOINOM GD) «chao Viso ek 2. dd eee ene ee 7,000 
eee is aos ke eke Geb ck does ee dvads 1,800 
Prep oim@en ms CUSMIGOTS, CLC... 62.6262 0206 50.0. ea ds 1,040 
PUTO R OSE fo ks. fcc eka Wk ad ada be ced eas 380 
Cash-registers and show-case fixtures ........... 1,390 
er Tes aARE COTY neo. sip 4 ale 6 wince + bc \ele vibe cclete ces 2,000 

eee Mare ear ech x oiaicoi gv a seis oaela wa evans 1,144,000 
B_ Service-Plant: 
Conveyors, hoists, and crane ...........0.ee000% 380 
Machine-shop and store-room .................. 1,000 
rae IN re PIS sc oc ep se sé t sles st eee 6,400 
ne, CAND STS ae oe nr ere en ah 3,400 
SMC PCR PTT fa ce es ces bebe bb ewe ap ve euanee 51,000 
Regulators, gages, and thermometers ........... 280 
RPP OM RN TRATLOCOL GS 66g sisg oe do cee ween eevee ea ee 13,070 
Expansion joints, traps, and valves ............ 5,690 
Venturi meters and pressure-tubes .............. 850 
CUS ovole ahi ili a 90 
PMI OPCEMOT Seiya hk x tba oo ce le wre le se oe 600 
Ee TOE OE Se ois a eis hin 5s ole hee He ne Oe 12,000 
Co nS a Pa 11,950 
Pea ees tO) sw wins on esi vi alae $f ee 1,160 
Rem Pen ICR CLG. © 1. 4. . wc Secs eels toe se te es ee 1,030 

iy re ela sie'y hilo ola to sia am 016.8 49)6,4 0 108,900 
C Sub-stations Nos. 1 and 1-A equipment: 
Sere te ge EI Re ay Si ck Sac ls ee Mele ele sew 64,000 
Se Mh Ne cg i 2 fac! pho far esa so bie 2 x obo ey com 12,000 
CLUES: fa 0 a Pe a 1,300 
SETA TE ina nese eo sh wk Pe ch aes 73,400 
RIE OTs oye sg Go nie bins See bin ele ee ee at 13,200 
RMA R MN, 6 ed rcs kin ses siete ad vv eels eee 29,500 
eae Reiko loc is Pie wy ed euends 6 vn ol agen e 217,700 
De Te yale oa ois kav ec dle oe ene ea 45,500 

et eens 5 kk yaa, eee epee ae bee's 456,600 
De-Yard: 
Ibighting and cables ..........56-ee cs eeceewee cs 396,200 
Mideninge, putters, CC. 0... ee ed ee tee een wees 78,650 
Se eR oogonia. aie Vigce.s Ss So kee ee ww 4,050 
Traps and valves .........--sscecseeeeccereeees 10,650 
Sewage-ejectOrs 0.2... cece eect cece cece ee eees 540 


Plumbing-fixtures ........+06- Cite te Nearer fotki 480 


266 THH STORY OF COPPER 


Pounds 
Trap-screws and floor-drains..), ../5....4 ese 3,200 
Hydrants and hose-couplings ...........f.0.see0.. 2,190 
Battery: charging ‘sets 45.5 4 + ss in3 8 ei oe 200 
Hlevyator \ baggage-trucks © ..'.).... 04» ncaa 1,480 
Mail conveyor equipment and signals ........... 5,300 
BALI PS 5 i sie ens 2.8 & af «) Gets dileier = eens: Spin hae le 780 
BlQUEP B38 555, oa eb woe Ra ees in Bite 250 
SORTER se snes. bleia'. con Oat ie eae 4 aie oe 240 
Floor: plates 5530s dies daia conde oily Sees ea 90 
Oil-room equipment /)0s. Gi. x uirs os eee ee 500 
ORAL ai sb 3.iolo Vie’ aie bd nd Sea teal vie a 504,800 
E Electrification, Signals, and Interlocking: 
Peedere:s 2 sk es os a's eee ee ek ee 22,100 
BOM Sih a sid) oiatlelovevasnie ol A2e alah salads glee chan en 33,400 
JUMPCTS ss cod vo eosin bbe abba e eat 58,900 
Galego ies bce bold cd dew acetessleomlern sole oan 118,000 
Interlocking machines. 4... 0:59 en oe 50,000 
Switeh machines: oi.) 2.5. bse \ ae 40,500 
Switch-machine ‘circuits \)..f. 1) a ee ee 148,500 
Control ‘cable’? osc eictvid cles ote aleiece a eR 1,600 
Telephone | cable! ii...) 05 66 daira. helene 1,500 
Fire-alarm: syatem.’ 4). 5... wy eee 1,700 
Total on nk So ead Bids Ga 476,200 
F Construction Department 
Temporary slanting (i... sve< abne eee nal wince Wie aes 12,500 © 
Valves, plumbing, ete. \. . 0.0.5 she sen ee 1,150 
Electric driven air-compressors .............-.. 7,000 
ErenAFOriiers (5o.cjaii ins eae nt lg ok care ee 4,300 
Pumps and ‘motors j.)5 v0 «'.\+)- eels a giclel tele eee 2,550 
Total oo cic'y vie’ inie bie nth e's buahe a hel a pio esata ern 27,500 
Summary: , 
AC Buildings oi) Cs, <0 aike she eng em er 1,144,000 
B). Service-plang a 6s. d:... aise ae 108,900 
C Sub-stations Nos. 1 and 1-A equipment .. 456,600 
De SVarde ees as Sa ae eg 504,800 
E_ Electrification, signals and interlocking .. 476,200 
F Construction department 4... onus eee 27,500 
Grand. total) \.3 2025 Ace ee 2,718,000 


The reader has hardly read all of the list, but the 
mere fact that half a ton of copper is used in the desk- 
fans in the Grand Central Terminal is impressive. 


BUILT OF COPPER 267 


From the examples that have been given it may be 
seen that the owners, designers, and builders of the 
larger structures have realized the economy of build- 
ing well with permanent material. The average home- 
maker who buys a ready-made house built for profit 
and not for permanence is likely to be enticed by 
temporary veneer, especially as the first cost of the 
less permanent house is lower. Because America is a 
land with roofs that must be painted, plumbing that 
rusts out, screens that crumble, because it is a country 
that must be continually rebuilt, it is estimated that 
$626,500,000 is wasted annually. Experts claim that 
copper and brass can save this loss occasioned by the 
repairs and replacements made each year on the ap- 
proximately twenty-one million residences in this 
country. 

The largest single factor in this great extravagance 
of America is the use of sheet-metal work that rusts out 
in about five years. The footage of gutters and leaders 
or downspouting in use would encircle the globe about 
forty times; or, if you would rather think of it in 
figures, there are 5,175,000,000 feet of leaders and 
oeutters not made of copper. In money, the loss caused 
by the use of iron and other inferior metals rather 
than copper for leaders, gutters, flashing, and valleys 
in residence construction amounts to more than five 
hundred million dollars annually. In making the sur- 
vey, it was estimated that the cost of replacing a rusted, 
useless piece of sheet-metal would be one and a quarter 
times the original cost because of the necessity of re- 
moving the unserviceable downspout, gutter, or flash- 
ing before repairs could be made. In arriving at 


268 THE STORY OF COPPER 


these figures for waste in building, it was learned 
through a careful survey that the average residence 
has 150 feet of gutters, one hundred feet of leaders, 
fifty feet of valleys, and 150 feet of flashings, and these 
were the quantities used in the estimates. Even the 
immense sum of five hundred million dollars does not 
include the wall-paper, plaster, and furniture damaged 
by an unexpected leak, which occurs every so often 
when rusting metal-work is used, nor does it allow for 
the damage done to the building in repairing the metal- 
work. The time and money lost and the trouble caused 
is a needless overhead similar to the repairs and re- 
placements. 

The water that is brought into the home through the 
plumbing is just as active an antagonist to iron as the 
rain that flows down the gutters and leaders. When 
the water is heated it becomes even more eager to re- 
lease its oxygen to unite with iron, and the result is 
that in a house with plumbing of iron the pipes will 
often run water red with rust, or hardly allow it to 
run at all. Eighty-six million five hundred thousand 
dollars is the annual fine that is assessed upon those 
who have iron pipes in their hot-water lines alone, ac- 
cording to the survey made to determine the saving 
that could be effected through the use of brass instead 
of iron. If the combination of copper and its junior 
partner, zinc, were used for the hot-water pipes, this 
expensive waste could be eliminated. 

Man is continually waging war on his most insidious 
foes, the lower forms of life. Armies of insects cause 
him trouble, particularly in summer. The aérial 
branches of those great omni-present hordes are best 


BUILT OF COPPER 269 


combated by erecting a protective barrier. If the 
War Department were in charge of protecting the 
nation against this enemy, it would go to Congress for 
an annual appropriation of thirty-two million dollars. 
That is the amount spent each year painting, patch- 
ing, and replacing screens to keep flies, mosquitoes, 
and other insects out of our houses. If screening were 
a part of the national defense program, a committee of 
producers of copper and bronze insect screens would 
probably go to the general staff and urge them to sub- 
situte their non-rusting products for the materials that 
quickly rust to uselessness, no matter how much is 
spent on painting, dipping, and galvanizing them. Be- 
cause of the lack of a central authority to purchase all 
screening, the builders and housewives are being 
shown the advantages of copper or bronze screens that 
will last as long as the house. 

Wastes in ordinary, built-in-a-hurry-for-to-day, 
American residence construction do not end with in- 
ferior sheet-metal work, iron plumbing, and rusting 
screens, nor with the damage that they incidentally do. 

Before the World War, brass and bronze were the 
accepted standard materials for locks, hinges, and the 
other common building hardware. But when war 
came, the copper and its principal alloys that were 
about to go into their regular peace-time service were 
drafted and turned into millions of rounds of am- 
munition. As there was not enough copper to fight the 
war and stay at home, too, substitutes came into the 
places that copper left behind. These substitutes, sad 
to say, were inferior. They would not stay on the job 
year after year. Their iron was always endeavoring 


270 THE STORY OF COPPER 


to run off with oxygen in a streak of rust. The manu- 
facturers realized that this was the case, and in many 
cases they kept enough copper at home to furnish a 
temporary guard on the outside of the substitute iron, 
but this veneer of brass over the iron, though successful 
in keeping a bright front until it was bought and placed 
on the job, could not withstand the uneasiness of the 
iron below. At the first scratch iron ran off with oxy- 
gen, regardless of the stain it created. Such condi- 
tions had to be put up with when the war was in prog- 
ress. When the war was over the substitutes for cop- 
per, brass, and bronze held on to their war jobs. 
Copper and his partners came home from war and 
found themselves without work; they were in the same 
condition as many of the soldiers with whom they had 
fought. Although during the war the substitutes were 
able to demand and get full copper wages on the 
strength of their brass veneer and the fact that they 
were badly needed, when the war was over and true 
copper products were again ready for peace-time work 
the substitutes found that they could work for less. 
And the builders, accustomed by this time to inferior 
work, kept the substitutes on the job and decided to 
let the purchasers of homes pay the loss at some later 
date. It takes a little time for inferior work and prod- 
ucts to expose themselves, and the path of least resist- 
ance is to continue to do things as they are being done. 
Now copper, brass, and bronze are ready for work at 
prices lower than before thé war, and by showing in 
cold figures the economy of their «service, they are 
winning back their rightful places in locks, door-knobs, 


BUILT OF COPPER 271 


and all the other kinds of hardware that should serve 
without trouble and expense as long as the house. 

People have the idea that copper is expensive. Per- 
haps their constant contact with pennies makes them 
hesitate to cover their roofs with the same material 
that is used in these coins. Whatever the reason, many 
look upon copper and its products as a luxury. 
They have never computed the actual saving in ex- 
pense that copper’s long life allows. But even if they 
do not wish to look forward and build for the future as 
well as the present, the added cost of using copper and 
its alloys is not prohibitively great. If you spend 
$1.0114 instead of $1.00 you can avoid perpetual leaks 
and renewals by using copper in leaders, gutters, 
flashings, valleys, and other sheet-metal work. For 
less than one cent added to the building dollar, brass 
hot-water piping can be installed instead of iron. 
‘Real copper, brass, and bronze hardware can be in- 
stalled adding less than 114 cents to the dollar, and 
for 234 cents added to every dollar a house may se- 
cure the continuous protection of a copper roof. 

There is a scene in the future that the builder seldom 
visualizes. When the building that is being erected 
to-day is superseded by another, when its usefulness 
is over, it must be torn down and the materials that 
have served together so long must be separated. Some 
bricks are sorted over and used again. But most of 
the building finds its way to the dump. Iron roofs 
that have been nursed along with numerous coats of 
paint then reach the end of their lives and are buried 
without regret in the rubbish of the dumping-ground. 


202 THE STORY OF COPPER 


Tron hardware, too, is seldom worth removing from the 
second-hand material. Iron pipe has only a very low 
value as scrap. But with copper or brass portions of 
the buildings, it is another story. The watchman on 
the job keeps a close watch over the copper-containing 
hardware and the brass pipe that is removed from the 
building, as the junkman pays money for old brass. 
and copper. Often locks, hinges, and other pieces of 
hardware find themselves again in service in new 
buildings, while those that have gone out of style with 
the passing years are sold and their red metal is turned 
again into the channels of commerce. A copper roof 
after years of service may find itself laid on the top of 
a new building, and if it ean not continue thus to defy 
the weather an old metal dealer will pay for the priv- 
ilege of rejuvenating it and transforming it into an- 
other copper product. Because of copper’s salvage 
value, the person who buys a copper roof can consider 
that he is placing money on deposit as well as saving 
the cost of construction with inferior metals. The 
purchase of diamonds is often considered a good way 
of investing money. A copper roof lends beauty to the 
house just as a diamond sets off a hand, and a copper 
roof is nearly as good a bank as the diamond. 
Durability, the same quality that results in high 
salvage value, is the cause of economy in the use of 
brass and copper in building. This quality of copper 
products is demonstrated not only by the unsystema- 
tized general observation of their lasting qualities but 
also by some planned investigations that have been 
made. A large manufacturer of wrought-iron pipe 
made a survey some time ago of the condition of hot- 


BUILT OF COPPER 273 


water plumbing in 128 Pittsburgh apartment-houses 
containing 996 apartments. The data justified his 
trouble and showed that wrought-iron pipe is better 
than steel pipe for plumbing, but it also proved so con- 
clusively the superiority of brass over both kinds of 
iron pipes that the brass and copper companies have 
used these same figures as the basis of an advertise- 
ment of their own. Although all the steel pipe had 
failed at the end of eleven years’ service, and all but 
one installation of wrought-iron pipe was worthless at 
the end of eighteen years, there was not a single brass 
_ pipe failure on record. The steel pipe began to fail 
at four years, and the wrought-iron after eight years. 

The labor cost of laying copper roofs has in the past 
been a hindrance to their use. Relatively large sheets 
were used, and they had to be laid by methods similar 
to so-called ‘‘tin’’ roofs. This necessitated making 
joints in places, and as copper is a little more difficult 
to work than tinned iron it took more labor to make the 
standing seams or other joints. Copper shingles that 
ean be laid more cheaply have recently been placed on 
the market to reduce the high cost of applying this 
material. Instead of large sheets, the roofing material 
consists of rectangles of copper, six or eight inches 
by eighteen inches, crimped so as to form a joint with- 
out any work at the installation. They are claimed to 
be lighter than any other substantial roofing material; 
they weigh only eighty-four pounds to the hundred 
square feet, compared with two hundred pounds for 
wooden shingles, four to six hundred pounds for 
asbestos, 750 to 1200 pounds for slate, and one to two 
thousand pounds for tile of the same area. Copper 


274 THE STORY OF COPPER 


shingles cost less than tile or slate, and only twice as 
much as wooden shingles. For those who do not care 
for the reddish shade of new copper or the green pro- 
duced by a few years’ weathering, these shingles come 
in seven different shades, four greens, a blue, a red, 
andabrown. Nature acts as the decorator of a copper 
roof. After she has tired of the copper red of a new 
roof, she often turns it to a rich green that blends with 
foliage, although occasionally she will form the black 
oxide rather than the green carbonate. ‘‘Patina’’ is 
the name of the green coloration; geologically speak- 
ing, it is malachite, copper’s carbonate, exactly the 
same as the ore. If the house owner is impatient and 
desires to have a green roof without the necessity of 
several years’ delay, the roofer can provide it in 
twenty-four hours by using a simple process. This 
is the formula: 

After the copper-work is completed, make a solution 
of one pound of sal ammoniac to five gallons of water; 
let it stand for one day and then apply it to the copper- 
work with a brush. This application is allowed to re- 
main one day, after which just enough clear water — 
should be sprayed to moisten the copper. The same 
results may also be obtained by using a solution of 
half a pound of salt to two gallons of vinegar. 

Even though a house is not protected and decorated 
by a copper roof, copper is often used in cornices and 
copings, sheathing around windows, flashings in con- 
nection with some other roofing material, and weather- 
strips. When less permanent materials are used 
virtually throughout, it will usually be found that the 
highest point in the structure is a copper lghtning- 


BUILT OF COPPER 279 


rod. In the case of store buildings of the better class, 
the whole front of the structure, show-window frame 
and all, is frequently made of sheet copper, brass or 
bronze, decorated in relief or repoussé. Brass and 
bronze facades are a much more common sight in 
Berlin or Vienna than in this country, in which most 
of the metal was produced. Bronze doors for banks, 
apartment-houses, and other buildings, which have be- 
come a permanent feature of German building con- 
struction, are an outgrowth of the medieval use of 
bronze doors for churches and cathedrals, and even 
the motion-picture theaters, hotels, cafés, and restau- 
rants have entrances or fronts of brass and bronze. 

Man is not alone in enjoying the advantages that 
the use of copper gives to buildings. In one of the 
larger magazines an advertisement may be found that 
describes a house for wrens, ‘‘made of solid oak, 
cypress shingles, copper coping, with four compart- 
ments.’’ It declares that ‘‘a regard for little details 
determines whether birds will occupy a house.’’ 

In most building construction, from the point of 
view of bulk and proportion of cost, copper and its 
alloys play a comparatively small part. But several 
structures erected in the busiest part of New York 
City are constructed almost entirely of bronze. These 
are the new traffic towers along Fifth Avenue from 
which the flow of more than 15,000 vehicles and 130,- 
000 pedestrians each day is directed. 

Many other classes of construction are bettered by a 
liberal use of copper and its products. In fact, when- 
ever a structure of permanent nature is erected, it is 
usually advantageous or necessary to use copper in 


276 THE STORY OF COPPER 


some form. This metal will be found in greenhouses, 
burial-vaults, and bridges. Engineers estimate that 
the use of bronze for a protective covering over the 
cables and all other steel-work of the $100,000,000 
Hudson River bridge to connect Manhattan and New 
Jersey will save four hundred thousand dollars an- 
nually in upkeep alone. 


CHAPTER XII 
COPPER IN THE HOME 


Now that we have learned about copper’s birth, 
training, and career, let us go into the house and see 
how often we meet it in our every-day domestic life. 

As we walk along, observing with a glance at the 
bronze-lettered lamp-post that we are on the right 
street, the verdigris green roof of the house stands out 
in the distance. Copper numerals fastened on a 
bronze plate or bronze-painted figures on glass tell 
us the number of the house, and we are helped up the 
steps by a railing of copper. Next door a brass name- 
plate announces that a physician is our neighbor. 
There is a polished brass knocker on the front door, 
but with some hesitation we decide that it is more likely 
to be ornamental than useful, and we announce our 
presence by pressing the brass button, set in a copper 
frame. Electrical impulses shoot through a copper 
wire to a bronze bell inside the house.. As we wait for 
the copper-colored maid to answer our ring we admire 
the copper leaders from the roof and observe that the 
hardware on the windows and the shutters is made 
of brass. Copper or bronze screens that have evi- 
dently served successfully for many years ornament 
as well as protect the windows that may be raised. 


By turning a brass knob which controls a brass lock 
277 


278 THE STORY OF COPPER 


the maid opens the door on silent brass hinges, and we 
are received in the house. 

If our minds are tuned to copper just as the radio 
receiving set we see in the parlor is tuned to a certain 
wave-length, we are likely to be astonished at the large 
number of objects in the house that will respond to 
such a test. We will adjust our eyes and minds so 
that they are selective to ‘‘a band of wave-lengths,’’ as 
the radio enthusiast would put it; we shall be on 
the watch for brass, bronze, and other objects, dis- 
guised or frankly copper-containing, as well as pure 
copper. 

Everything electrical about the house not only re- 
ceives its energy through copper but is also depend- 
ent upon the use of copper in its operation. Snapping 
on an electric light-switch allows the current to flow 
along copper wires into lamps supported by brass 
fixtures. If we step to the telephone the lifting of the 
receiver allows a copper-carried electrical current to 
notify the operator that we want a number. Although 
‘‘wireless,’’ the radio receiving apparatus snatches its 
music and entertainment out of the ether by means of 
wires, and copper conveys the impulses to the ’phones. 
Alongside the antenne of copper wire strung up on the 
roof, a copper lightning-rod can be seen pointing into 
the heavens. 

Rods over the windows that hold the lace curtains 
are brass, as are those over the doorway from which 
hang the draperies woven with a woof of bronze. 
Above the brass andirons in the open fireplace a pair 
of brass candlesticks are artistically placed, and in 
one corner on a pedestal stands a bronze bust. A 


COPPER IN THE HOME 279 


jardiniere of hammered copper on the other side of the 
room holds a fern. 

In the dining-room we know copper is hidden under 
a coating of silver in the Sheffield silverware on the 
table. The electrically heated coffee-urn and toaster, 
like the other electrical equipment of the house, are 
largely made of copper. A bronze dinner-bell is 
patiently waiting until dinner. In a golden brass cage 
hung in the sun there is a canary who plainly asks us 
to inspect the new house he has been given. If it 
happens that the house belongs to a family who can 
trace their kitchen utensils as well as their ancestry 
back for several generations, we shall find that many 
of the pots and pans are copper, lined on the interior 
with a heavy coat of tin, or coated entirely with a film 
of electrically deposited nickel. Even if the kitchen- 
ware is made of other materials, you may find that the 
sinks and drain-boards are coated with copper sheath- 
ing and that the hood over the stove is also made of 
this metal. If we examine the voice tubing through 
which the lady of the house talks to the kitchen-maid, 
we are likely to find that, too, is either copper or brass. 
Throughout the room, in wire brushes, in hardware on 
the ice-box, and in numerous other instances the red 
metal or its compounds are being used. 

In the laundry there are other examples of copper 
serving the home. Most of the important parts of the 
electric washing-machine are made of this non-cor- 
roding metal, and no material is quite so satisfactory 
as copper for the bottoms of wash-boilers. Within 
the casing of the constant hot-water heater there is a 
copper coil which suggests the reason why, if a rumor 


280 THE STORY OF COPPER 


may be credited, many more of these coils have been 
purchased during the last few years than have been in- 
stalled in hot-water plumbing-systems. This is a well- 
built house that we are in, and naturally all hot and 
cold water-pipes are made of brass. Our host is proud 
of the fact that a plumber has not been needed since 
the house was built. In keeping with the pipes, the 
spigots and other equipment in both laundry and 
kitchen are shiny brass. The alarm-clock that ticks 
loudly on the shelf and tells when to get dinner ready 
is run by mechanism of brass, and hung in a rack con- 
veniently is a shiny brass-sheathed fire-extinguisher 
ready for an emergency. 

As we go to the second floor, our copper-selective 
eyes pick out the brass-headed tacks that keep the stair 
carpet in place, and the golden design printed on the 
hall wall-paper also responds to the test for copper. 
In the bedrooms, there are brass beds, prized by our 
hostess because they are copper-containing through 
and through. And the casters on which they and the 
other furniture roll are brass. Here, too, as in the 
other rooms of the house, the electric fixtures are brass 
and bronze and all hardware is made of the same 
metals. On the dresser is a burnished bronze clock, 
much more refined than the kitchen alarm but ticking 
off the same seconds, and this is balanced by a photo- 
eraph encircled ina bronze frame. Our copper-detect- 
ing eye spots a small electric iron, a brush and mirror, 
numerous pins, the pulls on the furniture, and many 
other small objects made partly of red metal. The 
plumbing in the bath-room from shower to drain- 
pipes, though disguised by a coat of nickel, is truly 


COPPER IN THE HOME 281 


brass beneath. In the den of the man of the house, 
more copper can be found. On the desk finished in 
bronze there is an ash-tray stamped out of sheet- 
copper; the paper-cutter is fashioned from a brass 
rifle-cartridge, a memento of more strenuous times. 
In the corner a set of metal-headed golf-clubs includ- 
ing a brassie list themselves as containing copper, and 
the squatty trunk near-by is proud of its brass fittings. 
Sporting-goods, fish-reels, guns, all show their share 
of copper. 

Hiven the garden back of the house contains its cop- 
per. A fence of copper wire shields it from intruders. 
The sun-dial, exposed to the sun of summer and snow 
of winter, like the time-telling devices of the house, has 
copper in its make-up. The hose-connections, like 
the pipe that supplies the water, are made of brass. 
And even the bugs on the roses get a dose of copper 
when they are maliciously fed paris green, chemically 
known as copper arsenate. If we use a brass key to 
open a padlock of the same alloy leading into the 
garage, it will be seen that copper has been used in 
important parts of the automobile that this building 
shelters. 

If our search for copper is directed toward ourselves, 
we discover that the average human being carries a 
considerable amount of copper around with him. In 
virtually all of the metal we wear, copper plays an im- 
portant part. Good pins and snaps are made of brass 
with a coating of nickel. Belt buckles may be silver- 
plated over copper or may be made of a copper alloy. 
The trimmings of our fountain-pen and the case of 
our patent pencil are likely to be made of brass. ‘The 


282 THE STORY OF COPPER 


eyelets in our shoes, as well as many of the nails, are 
made of the same alloys, and this metal in our pres- 
ent shoes may remind us of the days when copper 
toes were worn for economy’s sake. No matter how 
genuine the jewelry may be, it contains some copper, 
if only to harden the gold and cause it to resist wear. 
Spectacle frames are similar alloys in which copper 
plays a minor or major part, and cuff and collar but- 
tons are basically copper in most cases. If our pro- 
fession calls for it we find ourselves wearing brass 
buttons on the outside of our coats, and, regardless of 
how we earn our livelihood, brass buttons may attach 
our suspenders. All of the coins that jingle in our 
pockets have some copper in them. If we carry a cane, 
you may be sure that the ferrule is brass either openly 
or underneath, and the head itself contains at least 
a small amount of copper. The pocket-knife, if it is 
well made, is lined with brass and fastened together 
with pins of the same metal. If the new evening-dress 
that your wife is designing for fresh social conquests 
has a metallic shimmer to it, you can rightly suspect 
that some copper-containing metal has been used in the 
weaving of its material. And of course the slippers 
obtain their brillance from the same source. ‘The last 
covering that is worn by all of us, a coffin, may be of 
bronze, or may have nickel-plated brass trimmings. 
If more modern methods of cremation are preferred, 
a bronze vase will preserve human ashes for centuries. 

If we could go back centuries and invade the house- 
holds of previous ages, there, too, copper would be 
found serving man. Wires that carry the bottled sun- 
shine of former times would be missing, and we should 


COPPER IN THE HOME 283 


feel the lack of electric door-bells and the electric 
coffee-percolator. But in those days copper found 
uses to which it is not now put. The mirrors that flat- 
tered the flapper were made of the shiny white alloy, 
two thirds of copper and one third tin, called speculum 
metal. And before this alloy was perfected, polished 
bronze itself, was used. Copper itself was prized as an 
ornament, especially among the races that were living 
in a bronze and copper age. When knights and ladies 
were real, not just romantic characters in books, 
Sunday-go-to-meeting armor was copper or copper- 
covered. A thousand years before the birth of Christ 
bronze safety-pins were used, prototypes of the modern 
ones made of tin-covered brass. : 

The modern architect, when he designs for combina- 
tion of permanence and beauty, naturally thinks of 
copper, brass, and bronze. The best mansions and cot- 
tages, built for the future as well as the present, con- 
tain much copper in their interior as well as in their 
walls. Of this practice, it is well to know that the 
gods of mythology as well as the common sense of 
science both approve. With spiritual satisfaction one 
may read in Bulfinch’s ‘‘Age of Fable’’: 


Everything of a more solid nature was formed of the 
metals. Vulcan was architect, smith and armourer, chariot 
builder, and artist of all work in Olympus. He built of 
brass the houses of the gods; he made for them the golden 
shoes with which they trod the air or the water, and moved 
_ from place to place with the speed of the wind, or even of 
thought. He also shod with brass the celestial steeds, which 
whirled the chariots of the gods through the air, or along 
the surface of the sea. 


CHAPTER XTIT 
DOING THE WORK OF THE WORLD 


For ages copper has been doing the work of the 
world. As time went on it acquired many new jobs and 
seldom lost one. As war became progressive, it took 
brass and bronze out of their menial positions in can- 
non and cutlass but made them responsible for more 
modern killing methods. Youthful electricity nearly 
Swamped copper with burdens to carry, and even now 
monopolizes more than half of its time. A thousand 
other tasks need copper’s aid, and they get it. 

Gold is the basis of our fiscal system, we are told. 
All values are based on the international price of gold 
per ounce. If gold furnishes the capital for our cur- 
rency, copper does the labor. But, unlike most co- 
operations of capital and labor, the relations of cop- 
per and gold are never marred by strikes or lockouts. 
Gold sits in its vaults safe and secure while other 
metals and paper slave in the counting-houses and on 
the exchanges, operating in gold’s name. Hven when 
the noble metal condescends to venture forth on some 
special occasion, such as a prize contest, a birthday, 
at Christmas, or in exchange of actual metal wealth 
by banks, copper must accompany gold to protect it 
from the rough usage that it encounters in the world. 


Silver, the second richest metal used in ordinary coin- 
284. 


DOING THE WORLD’S WORK 285 


age, also needs copper’s protection from the rub of 
human fingers and pockets. 

In every golden double-eagle or eagle, in every silver 
dollar, half-dollar, quarter-dollar, and dime, there is 
10 per cent. copper; they are 900 fine, as the assayer 
would say. If the names of coins were decided by a 
majority vote of the metals in them, the ‘‘nickel,’’ the 
American five-cent piece, would be called a ‘‘copper,”’ 
the name given tothe penny. The nickel contains only 
one fourth of its weight as the metal that gives it its 
name, and three fourths is copper. Once there was 
a time when the one-cent piece was quite properly 
named a ‘‘copper,’’ as it was made of pure copper. 
Now ‘‘bronze’’ would be more fitting and true from a 
metallurgical point of view, as the Indian and Lincoln 
pennies that are so fascinating to the youngsters of 
this age are made up of 95 per cent. copper and 5 per 
cent. tin and zine. According to the director of the 
mint, on June 30, 1921, there was $100,384,375.96 worth 
of minor coinage in circulation, stamped principally 
from blanks containing copper. This figure repre- 
sents the face-value of all coins issued since 1793 and 
not remelted at the mint. During the year 1920-21 the 
mint spent $437,428.70 for copper to be used for coin- 
age purposes. Virtually every country in the world 
uses red metal as well as yellow and white in its coin- 
age, and in China and other countries where wealth 
seldom filters to the bulk of the people the ordinary 
person hardly realizes that there is any metal in coins 
other than copper. 

Since the very discovery of metal, copper has been 
used as the medium of exchange. A copper weapon 


286 THE STORY OF COPPER 


probably was able to purchase by barter several 
archaic ones of stone. Later, chunks of metal came 
to have a definite meaning. An ox was worth some 
talents of copper, and at each commercial transaction 
it was necessary to weigh out laboriously that amount 
of metal. Soon this unneccessary labor became too 
much, and some ruler of politics or trade stamped his 
mark in a piece of copper as a sign that he had weighed 
it and found it worth so much. His people trusted 
him, just as citizens trust their government, and thus 
his monogrammed metal became the coin of the realm. 
It was natural that copper was the common coinage 
metal, and it was extensively used in the ancient world. 
Along with iron it was used very early in China, and 
it also figured in the early Hebrew coinage. Until 
269 Bs. c. it was the sole Roman coinage, and even after 
that time it continued to play the most important part. 
Gold and silver, though they cannot get along without 
a small amount of copper, are preferred as coinage 
metal as they have less weight and bulk for a certain 
-value. The famous Roman copper coin, és grave, was 
very thick, with a smooth plain reverse, and was always 
cast, unlike our modern coins that have their design 
stamped on a prepared metal blank. They also had 
the distinction of being worthless for practical pur- 
poses as they were made of peculiar alloy that reminds 
one of the occasional lead nickel that is encountered 
in our pockets: 70 per cent. copper, 19 to 25 per cent. 
lead, and about 7 per cent. tin. Other Roman coins 
were made of copper as pure as the usual casting cop- 
per of to-day. When brass was first made, it, too, 
was turned into Roman coin; one of the earliest ex- 


DOING THE WORLD’S WORK 287 


amples was a coin in the time of Augustus analyzing 
17.3 per cent. zinc. In point of composition our 
buffalo nickel has ancestors that existed before the 
Christian era, Bactrian nickel coins, which contained 
from 77 to 78 per cent. copper. Medals came into use 
when rulers wished to honor their subjects by giving 
them something of intrinsic rather than of monetary 
value, thus inspiring them instead of making them self- 
ish. Naturally the metal of the minor coinage was 
well suited to this use, and artistic copper and bronze 
is widely used to-day as a medal material. 

Copper, in addition to taking part in the financial 
transactions of a people, often acts as a conserver of 
wealth even when not given the stamp of authority 
that is necessary to turn it into coin. In Turkey, for 
instance, says a consular report: ‘‘Copper utensils 
constitute a form of savings bank among the poorer 
classes. What money they can spare is invested in 
copper utensils as an addition to their stock, and 
when they are in need of money they sell what can be 
spared of their copper according to their needs.’’ 
And here in America the large value of copper scrap 
that is rejuvenated each year is proof that the same 
process of investing money in copper and letting it 
pay interest by its service goes on whether we realize 
it or not. A man with a copper roof on his house does 
have more worldly wealth than one who is sheltered 
by a film of tin. 

To the more valuable metal in the coin, copper acts 
as a defender against abrasion because of the hardness 
that it imparts to the alloy. It has also been found 
that the copper of coins protects the health of the 


288 THE STORY OF COPPER 


people. Disease bacteria placed on a piece of paper 
seem to enjoy life, but when a copper-containing coin 
is placed on the paper not only the germs beneath it 
but those all around die from the effect of copper 
poisoning. There is probably less danger in a young- 
ster putting into his mouth a copper than many other 
commonly handled things, although the mouthing of 
coins is not to be recommended. 

If you want to buy bronze for industrial use, do not 
go to the bank and buy pennies. Uncle Sam does not 
care to have his carefully stamped metal used as bul- 
lion, and, what is more important to you, you will be 
losing money by melting up money. The Government 
exacts a very large profit on the metal that it turns 
into coins. It has a monopoly, too, as many in prison 
will testify. A one-cent piece weighs just forty-eight 
grains; there are 146 of them to the avoirdupois pound. 
The value of 146 pennies is $1.46. If one-cent pieces 
were scrap metal, 1434 cents a pound would be a very 
good price indeed, and you would probably have no 
trouble in getting ten pennies for a cent. With 1000 
per cent. profit on his raw material, Uncle Sam can af- 
ford to give us the best kind of service and art in the 
manufacture of coinage. But if the size of the penny 
fluctuated with the market price of copper, and was 
worth only its weight in copper, it would not be any 
more valuable to us in our commercial life; in fact, it 
would be more trouble on account of the greater and 
more variable size. 

The use of copper in our financial system does not 
end with the metal of our token currency. Every dol- 
lar bill, all the paper money of this republic, and the 


DOING THE WORLD’S WORK 289 


stamps that we use in preparing our letters owe their 
existence to copper. In smooth perfect plates of cop- 
per, an artist engraves the figures and lines of our 
paper money that so confounds attempts at counter- 
feiting. The money is printed by inking the plate so 
that the pigment will stay in the indentations and then 
transfer itself to paper brought into contact with it. 
Recently modern electrolytic methods have replaced 
the hand engraving that was formerly necessary in 
making copies of the printing plates. By very care- 
ful application of electroplating, exact duplicates of 
the master plates are made as often as desired. 

For reproducing announcements of high quality, a 
method is used similar to that employed by the Govern- 
ment in issuing its promises to pay. But copper 
enters into less expensive duplications, that of ordi- 
nary printing by the impression of ink-coated copper, 
and the illustrations of this book are printed from cop- 
per plates. First, in the forms of these letters were 
cast soft type-metal made largely of lead. Then the 
resulting type was locked up into pages, and sent to 
the electrotyper. Soft type-metal printing faces are 
good enough for job-printing and newspapers where a 
clear, clean-cut impression is not required, but for 
book-work copper is needed. A copper electrotype is 
made of each page and. the actual printing done from 
that. The illustrations are photographed on a piece 
of copper, and the necessary relief is produced by al- 
lowing acid to eat away the light non-printing part of 
the plate. Shades and shadows of the half-tone are 
obtained by photographing the picture through a very 
fine screen, causing the printed illustration to be made 


290 THE STORY OF COPPER 


up of very fine dots that are blended into an unbroken 
picture by the eye. When the book is printed and 
bound, it may be that letters of gold are selected to 
proclaim the contents. In most cases the imprints on 
the front cover and the back are colored with a yellow 
copper alloy, not real gold, combining inexpensiveness, 
beauty, and utility. 

Copper plates are also used for printing purposes 
by that combination of artist and printer, the etcher. 
The etching plate is the medium for a particular kind 
of drawing whose technique and results are entirely 
different from those of other kinds of art and printing. 
Kitching is accomplished by the eating away of a sub- 
stance by acid or other chemical. A plate of copper is 
first covered with some resistant material, usually 
wax or resin. Various methods are employed to get 
an even coat all over the plate: sometimes the 
‘‘oround’’ is melted and run or sprayed on, some- 
times a solution of it is poured on and the liquid 
evaporated. When a good coat of ground has been 
prepared, the artist is ready to begin his drawing. 
He puts in his lines with a sharp stylus, not merely 
cutting through the wax but digging into the metal of 
the plate besides. The proper scratching of these lines 
is of the greatest importance. The plate must be held 
firmly and the stylus pushed away from the artist; not 
toward him, as with the pencil in drawing. The cop- 
per dug out of the line is pushed up as a tiny furrow, 
and this must be of even height if the line is to appear 
smooth, for it forms the channel that holds the ink. 
In theory, the etching is not very different from the 
ordinary zine line cut used in newspapers. But the 


DOING THE WORLD’S WORK 291 


care expended by the artist in making the plate gives 
a very different result. It is well known that in the 
line cut no variation in shade is possible. Shadows 
-must be indicated by lines at varying distances apart, 
or by cross-hatching. The etcher uses the same 
devices, but he contends that he is able to make a dif- 
ference in the blackness of his lines by the depth to 
which they are dug with the stylus or ‘‘bitten’’ with 
the acid. Certainly, he can make them look blacker 
by making them wider, and the effect of gradation of 
light and shadow in an etching is often of extreme 
delicacy. Having put in the lines as he wishes them, 
the artist now calls in the acid to deepen his lines and 
bring out the picture. He uses nitrous or nitric 
acid. Now, the effect of all acids on copper is unique, 
and that of nitric acid is the most peculiar of them all. 
It is no wonder that the artist Joseph Pennell, in a 
treatise on methods of etching, laments that one never 
knows how the acid will work; that the same solution 
will never work in the same way on different days, nor 
on different plates the same day. The secret lies in 
the chemical characters of the materials used. The 
molecule of nitric acid has more oxygen than it is ex- 
actly comfortable with, and goes about trying to make 
some other molecule a present of some of it. The 
copper is not particularly eager to take it, but is 
willing to do so. So this transaction is carried out 
quite aside from the main business which is to form 
copper nitrate and set hydrogen free from the acid. 
Then the hydrogen which is set free begins to attract 
whatever oxygen is at liberty, in order to form mole- 
cules of water, and the result is a grand mix-up. All 


292 THH STORY OF COPPER 


the molecules show considerable excitement, but 
whether the copper in the furrows forms the nitrate 
and moves off into the solution or forms the oxide and 
settles down where it is, thus hindering the ‘‘biting,’’ 
is left very much to chance. About all the artist can 
do is to set the pan on the stove if biting is too slow 
or add some water if it is too rapid. It is easy to un- 
derstand that a good plate is viewed by its maker with 
rejoicing. After the lines are bitten to sufficient 
depth, the wax is removed by dissolving it in turpen- 
tine. Now the artist can tone his backgrounds and 
shaded spaces on which no lines were drawn. A little 
acid is painted on them with a chicken feather and al- 
lowed to remain a few moments. When all is satis- 
factory, the plate is inked and put into the press, and 
impressions are pulled. The careful etcher pulls his 
own prints, and studies each one carefully, for each 
will differ slightly from all the others. The art of 
etching is for patient, painstaking men. Not many 
have succeeded in this field, but those to whom the work 
is congenial find a never-ending fascination in the 
vagaries of their chosen medium of expression. 

Copper in coins carries value from place to place; 
copper in printing processes helps to spread human 
thought; and copper in wires carries human -speech. 
Copper also aids importantly in the physical trans- 
portation of goods and passengers. 

There once was a time when clipper ships sailed 
sturdily to sea, copper spiked and copper sheathed. 
Those ships have ended free careers on the high seas, 
but many of them are trailing behind puffing tugs, 
bowsprits gone, hulls defiled by dirty coal. They are 


DOING THE WORLD’S WORK 293 


still doing service, thanks to the materials and the 
manner in which they were built. Sometimes the older 
generations of ships grow too old in service, their 
ends come, and they must pass out of this world in 
flame as wooden ships of our navy and merchant 
marine usually do. This was the recent fate of the 
oldest ship of the United States navy, the Granite 
State, formerly the New Hampshire, whose hull: was 
laid down 108 years ago. Through Hell Gate to a 
lonely beach, the old veteran was towed. There it 
was burned for the wealth that was in it, the metal 
that gleams like gold and serves as long. Salvagers 
greedily took the burnished throne on the poop-deck, 
and stripped off the hammered copper sheets that had 
resisted the sea since 1846. Before the Civil War, the 
frigate Richmond was built in Norfolk, also of wood 
but metaled with copper. The other day the old war- 
ship quite properly came to the end of its career and 
was sold for the copper that its hull contained. 
Twenty-two thousand five hundred dollars was the sum 
offered by a junk-dealer for the Richmond. In the 
ease of two hundred wooden ships built only a few 
years ago, the offer for each was less than one tenth 
as much, $2100. At Annapolis there rides at anchor 
the famous yacht America, winner of the international 
yacht races in 1851, and the brass gear with which she 
was manceuvred to victory is still giving service. 
Marine use of copper was not monopolized by the 
wise old skippers of the past. The ocean palaces of 
to-day, though their shells are of steel, need many 
times the amount of red metal needed by the ships of 
the past. The modern battle-ship, like the modern 


294. THE STORY OF COPPHR 


army, feeds and talks on copper. A million pounds 
of sea-resisting, copper-containing castings, about 
500,000 pounds of sheet and tube copper, and about 
250,000 pounds as the material for its electrical nerves 
is the demand of the modern fighter of the seas. Pro- 
pellers of bronze often require 40,000 to 50,000 pounds 
of metal. Such a floating city uses copper for all the 
reasons for which it is preferred on land, with its in- 
corruptibility in the face of the salt of the sea as an 
added inducement. In the automobiles of the water, 
the motor-boats, copper is particularly useful for 
tanks, tubing, sheathing, shafting, rudders, nails and 
rivets, and all other metallic parts. A forty-five-foot 
cruiser will contain about 1300 pounds of red metal. 
Brass and copper are standard for marine use. Dur- 
ing the war iron substitutes necessarily fitted a large 
part of our emergency fleet, but this metal has proved 
itself unsatisfactory in the face of only a few years’ 
service. The older ships were sheathed with copper 
to preserve the wood in their hulls and to fight barn- 
acles and other sea life. The same insecticide qual- 
ities of copper are utilized in coating the steel hulls 
with marine paint compounded of the waste copper 
oxide produced by the copper rolling-mills. 

For more than a dozen years a strange craft has 
been sailing all the seas carrying a scientific crew. 
The brigantine Carnegie is the world’s only non-mag- 
netic ship; it was specially built by the Carnegie In- 
stitution of Washington to chart the magnetic forces 
as they prevail over the oceans, so that the mariner’s 
compass may direct him unfailingly, night or day, in 
cloud, fog, or fair weather. Hardly an ounce of iron 


DOING THE WORLD’S WORK 299 


or steel is allowed on board. The hull is of strong 
white oak, yellow pine, Oregon pine, and teak, fastened 
with copper and tobin-bronze bolts, composition spikes, 
and locust-tree nails. Four anchors of manganese 
bronze, weighing 5500 pounds, are let down by hemp 
cables through bronze hawser pipes. All the metal- 
work on the spars, rigging, and blocks of its brigan- 
tine rig are of bronze and gun-metal. The hundred 
horse-power engine called upon when the breezes die 
is built virtually of non-magnetic metals, chiefly bronze 
and copper, and the galley range is entirely copper- 
containing. The boats, two twenty-foot whale-boats 
and one sixteen-foot gig, are as non-magnetic as the 
ship itself. For months at a time the crew has lived 
happily in its non-ferrous boat, making observations 
with instruments uninfluenced by iron. And in the 
research centers on land, wherever scientific work is | 
being done, copper, brass, and bronze are valued and 
used for their many good qualities. Lack of magnet- 
ism is only one of these. 

Beneath the sea and in the air, there sail ships which 
are dependent upon copper. Inside the strong steel 
shell of the submarine is a maze of intricate machinery 
controlled through copper and driven by energy that 
must first become copper-carried electricity. The 
tubes of the fuel, pump, and trimming lines are copper, 
and the torpedoes that the submersible discharges have 
hundreds of copper parts. In the construction of a 
dirigible, a capital ship of the air, lightness must be 
combined with strength. As aluminum’s junior part- 
ner, copper strenthens the duralumin alloy from which 
the framework is made; and in the case of the ZR-I, 


296 THE STORY OF COPPER 


constructed by the United States navy, seventy miles 
of the strongest possible copper wire are being used to 
tie the sections of the polygonal framework and give it 
superior strength. The engines of the ZR-IJ, like all 
other gasolene engines in the world, will need copper 
in their construction, just as will those of the swifter 
aeroplanes that will circle about her. 

For America’s growing fleet of automobiles and 
trucks, from twenty to two hundred pounds of cop- 
per per car must be supplied. specially in the fuel, 
lubricating, and ignition systems, copper products are 
supreme, although in other parts of the car substitutes 
crept in during the war and the period of keen competi- 
tion in the automobile field. In one high-grade car, 
copper is used in the following parts: radiator- 
screens and oil-screens, aluminum castings (about 8 
per cent. copper), valve bronze for cocks, bearings, 
washers for thrust purposes, tubing for gasolene lines, 
liners for shims for connecting-rods and other places, 
connecting-rod pin bushings, on the manifold in the 
form of wire, asbestos gaskets and brake-linings, nuts 
and screws in various places, bearings in the clutch 
throw-out, carburetor (almost entirely of brass), hub- 
caps, various oilers, bonnet-lock plates and handles, 
radiators, hinges on the bonnets, wire for the electric 
lighting and starting system, instrument-cases and 
windings, primer valves, oil-pipes, number-plates and 
name-plates, lamps, starting and lighting generators 
and motors. Each year the automobile industry re- 
quires about 150,000,000 pounds of copper, about one 
thirteenth of the total consumption. It is significant 
that the easy-going pleasure-cars use less red metal 


WaddOO HLIM GaAOOA “SHUVWANVI S.MUOA SHTHNLINAD AOA 
MUN AO LSHCIO AHL AO ANO ‘HOUNHD ALINIYL UASANVdV( AHL AX GHAdIHSYOM VHAGNA AZNOUA V 


WEIGHTS DATING BACK TO THE TIME OF WASHINGTON 


These weights and measures once used in Virgina are inscribed “County of 
Maitfax, 9744, 7 


KETTLES THAT HAVE BEEN HISTORY 


Both of these tea-kettles date back many years. One of them has brewed tea 
since 1700. 


DOING THE WORLD’S WORK y ASH 


than the harder-working tractors. One of the largest 
manufacturers who makes both pleasure-cars and 
tractors places three times as much copper in the more 
agriculturally inclined vehicle. Copper license-tags 
for automobiles are a possibility of the future. Three 
of the largest copper-producing States, Montana, 
Michigan, and Arizona, are being urged to show state 
pride by using non-rusting tags of red metal, and the 
failure of sheet ferrous metal tags to last their allotted 
year in several cases has given an impetus to this de- 
sire. The additional cost per pair would be about 
eighteen cents. 

The railways of this country, though they do not use 
a quantity of copper equal to that required for high- 
way transportation, are one of the large consumers. 
A locomotive for domestic use needs from 134 to 2 tons 
of copper in its construction, including ninety-five 
pounds for the very essential bell. If this gigantic 
piece of mechanism is going abroad to do its work it 
will consume three tons of copper, as European prac- 
tice usually requires fire-boxes and stay-bolts of cop- 
per. Another important use of copper on the rail- 
road is in bearing metal for freight and passenger 
ears. For this purpose an alloy of about three fourths 
copper is used, and one thirtieth of the total of the 
- country’s consumption is thus used. 

Throughout the whole industrial world copper like- 
wise takes part in the alloys of bearing metals, or any 
parts that may come into contact with friction. 
Engines of all descriptions need various amounts of 
it. Another place where it makes itself useful is in 
parts for pumps and fittings handling all sorts of cor- 


298 THE STORY OF COPPER 


rosive and dissolving liquids, such as mine-waters, 
alcohol, aluminum sulphate, various salts, glycerin, 
heavy petroleum oils, brine and sea-water, sewage, 
vinegar, and many others of industrial and chemical 
importance. In valves for pipe-lines a large quantity 
of copper finds its calling each year, for, while iron 
and steel can be used in the pipes, the essential por- 
tions of the valves are most safely made of bronze. 
In the manufacture of food products, chemicals, dyes, 
candy, and drugs, copper is a metal of importance as 
utensil material. Copper’s high heat conductivity 
stands it in good stead in this use. When the distil- 
lery flourished in this country much copper was used 
in the worms and stills. Large brewing kettles that 
made beer in those days now turn out near-beer or 
ice-cream. Wherever cooking is carried on exten- 
sively, as in large hotels or restaurants, copper finds 
extensive use in kettles and utensils of all sorts. The 
juice heaters and evaporators of sugar factories are 
made of copper, and there are copper vats and rolls in 
pulp and paper mills. Tons of wire cloth are used 
every week in the paper industry, in the form of Four- 
drinier cloth. The liquid pulp is run upon this cloth, 
and the water drains through the meshes. The cloth 
has a comparatively short life and is soon valuable 
for scrap. The wire is made from a mixture of cop- 
per, zine, and tin, containing about 80 per cent. copper. 

Electrodeposition has found important industrial 
application through its ability to build coats of cop- 
per upon metal. The newest field for copper coats is 
that of repairing worn metal parts, such as pump- 
sleeves, ball-races, and aéroplane engine cylinders. 


DOING THE WORLD’S WORK 299 


Through the power of exact duplication that is pos- 
sessed by electrically deposited copper, the master 
parts of adding-machines and other such intricate 
mechanical devices can be reproduced over and over 
again without harm to the precious standard. 

The pin industry, numbering its products by the 
billion, is virtually the only one in which there is little 
or no salvage of brass, although it is estimated that 
two million pounds of copper enter this field each 
year. Now, copper-containing pins represent only 
about half of the total number of pins sold in this 
country, for during the times of copper shortage so- 
called ‘‘steel’’ pins, made of iron, have made their way 
into the stores of smaller towns and cities. Some re- 
tailers prefer them, as they can charge brass pin prices 
and make a greater profit on them, but steel pins are 
likely to rust and damage the goods in which they are 
used, especially in areas near the sea-coast. Many of 
these steel pins are sold to those who ask for those of 
superior brass. Both the brass and steel pins are 
coated with tin and present the same exterior to the 
public. Saftety-pins are made of all brass when they 
are for use exposed to the salt of the sea air, but the 
best safety-pin is a nickel-plated combination of 
springy steel shaft, with a brass case to conceal and 
protect the pin-point. 

The cheap alarm-clock ticking on the kitchen shelf 
and the world’s largest clock on the Colgate factory in 
Jersey City are brothers in the use of copper. If a 
watch or clock is made to supply the demand for an in- 
expensive article, nearly all of it will be of brass, but 
a time-piece that is the best that money can buy will 


300 THE STORY OF COPPER 


have gear-wheels and pinions of brass and usually an 
enameled brass face. The large clock that stares 
across at New York.and can be read three miles off is 
copper, brass, and bronze from its hands to its wheels. 
Copper corrects the time of the world just as efficiently 
as it keeps it. Each hour from the Naval Observatory 
at Washington a time signal is sent out over thousands 
of miles of copper wire to regulate electrically wound 
clocks in all parts of this country. 

The same qualities of brass that cause it to be used 
in time-keeping make it the standard material for the 
weights that measure our food and clothing and the 
other factors that enter into our daily life. The 
national standards of weight stored in a vault at the 
Bureau of Standards are made of platinum and are 
so highly treasured that they are rarely used. For 
practical purposes weights of brass, sometimes nickel- 
plated, on lever scales with critical parts of brass, are 
just as good and less expensive. Before the Revolu- 
tionary War, Fairfax County, Virginia, placed a set 
of brass weights and measures in use as its standards. 
In the following years they at some time fell into dis- 
use, superseded by others fashioned on more exact 
standards. But the old set, recently unearthed, is 
virtually in the same condition as when it was first 
made. | 

Beside the scales in the shop of to-day there will be 
_found a cash-register to keep account of the copper- 
containing coins which are taken in during the course 
of trade. Bills of sale are penciled and corrected with 
a lead-pencil whose eraser is bound to it with brass. 
Cash registers consume about one tenth of 1 per cent. 


DOING THE WORLD’S WORK 301 


of this country’s copper, and the pencils, clips, type- 
writers, and other equipment of offices consume a 
smaller but still important amount. 

The thousands of articles that fill the shelves of the 
hardware stores and come within that all-inclusive 
term of hardware are also avid consumers of copper. 
Should you get hold of a hardware catalogue on a 
rainy day you might pick out a list of articles contain- 
ing copper that would run like this: hatches, jointers, 
railing, gaskets, valves, pumps, trays, fencing, screens, 
brackets, kettles, tacks, locks, keys, butts, turns, 
casters, colters, dot rollers, hooks, levels, chain, lamps, 
bells of all kinds, vases, lubricators, pans, traps, gongs, 
brass-plated shoe-nails, candlesticks, plumb bobs, rail- 
ing fixtures, hose-couplings, hose-clamps, hose-racks, 
hose-reels, wire cloth, cuspidors, coffee-pots, spikes, 
latches, oil feeders, ice-box hinges, letter-boxes, hose 
menders, hose nozzles, rules, copper, brass, and bronze 
tubing, grilles, copper, brass, and bronze wire, pins, 
nuts, molds, screws, bolts, scales, pails, gun imple- 
ments, cartridges, tape-measures, expansion-joints, 
lawn-sprinklers, boiler-couplings, oil-cans, oil-cups, 
erease-cups, screw-eyes, wash-room fixtures, percola- 
tors, bronze rope, plate, injectors, door-checks, cup- 
hooks, coat-hooks, screw-hooks, hooks of all kinds, 
pipes, thermometers, fenders, toy electric cars, staples, 
copper and brass sheets, catches, copper bottoms, fer- 
rules, nipples, cages of all kinds, pinions, oilers, 
filters, hinges, washers, padlocks, expansion-bolts, 
patent letters, show-cases, handles, nails, boilers, 
eronnets, funnels, soldering coppers, steam-whistles, 
indicators, lanterns, chafing-dishes, knobs, floor-plates, 


302 THE STORY OF COPPER 


bull-rings, pipe-fittings, guides, edgers, water-gages, 
water-columns, bird-cages, fire-guards, springs, pulls, 
rivets, torches, horns, shot-shells, burrs, automobile 
flexible tubing, bronze safety chains, and automobile 
appliances of all kinds. 

When the work of day begins, when noon arrives, and 
when the end of work has come, these times may be an- 
nounced by the playing of chimes or the ringing of 
bells. Bronze, so often used for the purpose that it 
is called bell-metal, is more important in shape than in 
composition for rich-toned bells. Usually the copper 
content is about 75 per cent., but much more concern 
is Shown over the relation of height to width and the 
thickness of the metal which will determine the note 
when the bell is struck. The bell industry would not 
appear to be a very large one on first consideration, 
yet the consumption of bronze for this purpose during 
the years 1900 to 1915 ran from 750,000 to 1,000,000 
pounds a year. Copper, which has no day of rest from 
its task of doing the work of the world, often summons 
congregations to the churches. A typical set of church 
chimes weighs about ten thousand pounds. It is as- 
serted that bells cannot be made without straw. The 
molds are lined with a thin layer of straw. As soon 
as the molten metal is poured in, the straw is charred, 
but its presence allows the necessary room for a slight 
expansion of the metal. It is said that neglect of this 
precaution developed the strains which cracked the 
Liberty Bell under its violent ringing. Without this 
defect of manufacture it is probable that not even the 
excitement of independence could have caused a cop- — 
per-containing bell to fail at such an important time. 


CHAPTER XIV 
COPPER’S COMPOUNDS 


Copper’s universality from a utilitarian point of 
view is matched by the variety of forms which it as- 
sumes in order to do the work of the world. As un- 
aided copper it is preéminently useful; as the major 
member of numerous alloy partnerships it has many 
more valuable qualities. As metal or alloy, its rose 
red, golden yellow, and bronze are both artistic and 
practical; when united in the bonds of chemical friend- 
ship with many of the other elements of this earth, 
copper produces blacks, blues, greens, browns, and 
golden yellows that are decorative and industrially ap- 
plicable. 

The brilliant blues and beautiful greens of copper 
salts have always made them important colors for the 
painter. A number of copper’s compounds are manu- 
factured to-day for this purpose. Blues of two shades 
are made from the hydroxide and the sulphate; greens 
are obtained with the carbonate, the familiar mineral, 
malachite, and the still more familiar Paris green, 
whose proper name is cupric acetoarsenite. Shades 
intermediate between green and blue are produced by 
less common compounds: the arsenite, the borate, and 
the subacetate. Copper fluoride is used in some blue 
enamels. | 


Few of these shades are obtainable from substances 
303 


304 THE STORY OF COPPER 


occurring naturally. We do not realize, perhaps, the 
extent to which the dyes and pigments which make our 
world a beautiful place are made in man’s laboratory 
instead of nature’s. The surroundings of savages are 
quite.colorless beside ours. If we imagine the rude 
people of antiquity, just waking up to the beauty of 
wood, sea, and sky, suddenly grown aware of the drab- 
ness of their cave walls and tents of dried skin, we 
understand how paint happened to be man’s earliest 
step in civilization. There were not many colors 
available for his palette, but the dull reds and yellows 
of ocher and the blues and greens of malachite, cop- 
per, and its associates, with black from charred bones 
and white from friable limestone, or chalk, gave to the 
savages that could find all of them considerable play 
of ingenuity in combining them. 

Thousands of years before the earliest recorded 
history, there lived in the limestone caves of France 
and Spain a race of people whose drawings and paint- 
ings are among the marvels of the world. It is sup- - 
posed that artists of the ancient Cromagnon race were 
responsible for making these pictures. To them, 
then, belongs the credit of inventing paint. While the 
Cromagnons did not work with greens or blues, it is 
extremely probable that some early artistic people 
found the brilliant colors of copper’s ores as useful as 
the more commonplace reds and browns of iron and 
the white of chalk. Perhaps this happened many 
thousands of years before metallic copper was — 
achieved; the prehistoric painter may have been the 
first true user of copper. 

Paint in brilliant colors was of major importance in 


COPPER’S COMPOUNDS 309 


the personal and tribal life of the American Indian. 
The redskins mined ocher and hematite ores of iron 
with which to paint their faces, legs, and bodies a more 
terrifying red. Red stood for war with them, just as 
it means revolution to us. But, when a cosmetic that 
would please the gods was desired, they searched out 
the blues and greens of the earth, which, unknown to 
them, carried the same kind of metal that composed 
the weapons with which they were armed. In their 
primitive manufacture of face and scenery paint they 
took the flashy carbonates of copper and ground them 
fine. These blue or green powders they mixed with 
gum of the pine-tree. From the yellow squash of the 
fields they took the seeds, chewed them into a sticky 
pulp, and spat the binding concoction into the colorful 
mixture. Thus was Indian paint made to be spread 
on bodies and offerings to the great spirits. For the 
Indian, copper painted the sky of his altar blue, it gave 
the growing green color to his pictorial vegetation; all 
that was good and spiritual was represented in the 
green and blue of copper’s compounds. 

When historic times at last came to the earth, we 
find the Egyptians decorating their buildings with 
fresco-like paintings. Their pictures were made on 
plaster, but were for the most part line drawings filled 
in with colored wash, not shaded. Ceilings, especially 
of the temples, were made to represent the sky and 
dotted with five-pointed stars, painted in yellow on a 
blue ground, azurite pigmented. In the years that 
have since passed, the surface of the sky has turned 
to a green film of malachite, but when this is scratched 
the original sky-blue shines through. The Greeks 


306 THE STORY OF COPPER 


used paint, much of it copper, on their buildings, and 
especially on their statues. The latter were made to 
look as lifelike as possible, and the hair was often 
gilded with pure gold. The statue’s armor was real, 
made of bronze and fastened upon the figure. 

In the middle ages came a great development of 
picture-painting methods. Artists began with wall- 
painting, and learned to apply pigment to wet plaster 
as fresco. This is the only branch of painting where 
a vehicle for the pigment is not needed, for the colored 
substances combine directly with the plaster. Care 
is necessary in the selection of pigments for such 
works, for the chemical action between some pigments 
and the lime gives very unexpected colors. Wooden 
walls, as well as plaster, were adorned by medieval 
artists, and after walls they turned to specially made 
panels upon which their pictures could be moved from 
one place to another. Only at a very recent time 
were wooden panels replaced by the artists’ canvases 
with which we are familiar. Painters until recently 
ground their own colors in oil carefully by hand, or 
let their apprentices, who were learning to be artists, 
do it. The same principles are used to-day, although 
erinding and mixing are done mechanically, and paints 
for every purpose may be bought ready for your 
brush. The staple pigments are still the same as 
those used by the artists whose works have come down 
to us through the ages. 

Of nearly the same antiquity as the art of picture- 
daubing is that of pot-making. The troglodytes who 
drew the deer and bison upon their cave walls may 
very well have possessed only stone knives for their 


COPPER’S COMPOUNDS 307 


household equipment, and have eaten their chunks of 
venison from the cave floor. But man did not advance 
very far beyond the status of the beast before he dis- 
covered that he could fashion sticky wet clay and dry 
it in the sun or by the camp-fire and so add to his ap- 
purtenances a line of pots and pans which were im- 
mensely useful for storing food. The earliest kinds 
of pottery were simply dried mud. But even with 
such simplicity there was opportunity for interesting 
variety. 

_ Copper ores, as we have seen, have the deceptive 
habit of staining green the near-by ground. It is 
possible that some early savage living near such a cop- 
per deposit may have used this tinted clay for a bowl 
to grace a chief’s banquet-table, or to hold bloody liba- 
tions to some crude devil-god. But, if so, the vessel 
has perished. We cannot connect the use of copper 
salts with early unglazed pottery. Red, buff, black, 
and, more rarely, white are the only colors exhibited 
by such ware. 

When the curtain of history rises on ancient Egypt 
we find the potters already so far advanced that they 
possessed the art of glazing. Although their pottery 
underneath was poor stuff containing scarcely any 
clay, they applied a beautiful turquoise blue glaze, 
whose color is due to some copper salt. The EKgyp- 
tians made the older styles of pottery also, but this 
blue glaze seems to have been their own invention. It 
was developed as time went on; different salts were 
used from time to time, giving varying shades; decor- 
ations in other colors, notably the dark purple or black 
of manganese, were placed upon its surface; and the 


308 THE STORY OF COPPER 


blue glaze was even added to objects made of stone. 

From Egypt the ceramic art spread on the one hand 
to Greece, and thence to Europe, and on the other to 
Asia, where it has flourished not only for utensils and 
works of art but for architectural purposes as well. 
Whole temples in India and China are faced outside 
and in with beautiful polychrome glazed tiles, with the 
blues and greens of copper salts always much in evi- 
dence. 

The vases and other articles of Greek pottery were 
decorated with surprisingly few colors. This is some- 
what disappointing after the large number of colors 
used by the Egyptians. But the remarkable quality 
of Greek ceramic ware lies in the beautiful workman- 
ship which its makers put into the common materials 
that were at hand. Ordinary red or yellow ocher 
colored their clay, but they refined and mixed it with 
greatest care, and produced vases of beautiful red and 
orange colors. For a long time the Greeks used as 
decorations only a black coating, whose composition is 
not definitely known, laid on like paint. Much of their 
finest work was done in red and black only. Poly- 
chrome work was made, however, to some extent. The 
vase was first given a coating of fine white clay, which 
was fired, and then the figures were put on with purple, 
yellow, blue, and green. The latter colors are believed 
to be due to artificial compounds of copper and were 
not fired after they were put on. Vases of this char- 
acter were made about the fifth century B.c., at the 
time when Greek ceramic work was at its best. Some 
blue-glazed work, of the same character as the Kigyp- 
tian, was made, also, and, quite late, lead glazes 


COPPER’S COMPOUNDS 309 


colored green with copper oxide appear in the relics 
of Greece. ; 

When Rome succeeded Greece as the leader of 
thought of the ancient world, Greek ceramic art had 
reached a period of decadence. It was being replaced 
in popular favor by metal dishes, which had then be- 
come cheap enough for fairly common use. The 
potters, however, saw an opportunity, and made their 
ware as much like the more expensive metal dishes 
as they could. Such vessels were no doubt sold to 
poor people with the assurance that they were ‘‘just 
as good as metal.’’ 

Other colors than green or blue are added to fired 
clay by copper. In combination with other oxides 
copper helps to produce enamels of black. On old 
Chinese porcelains a peculiar red glaze has been found, 
called Chinese red, sang de beuf, or ox-blood, and this 
has been found to be due to tiny particles of metallic 
copper formed in the glaze by reduction of its copper 
oxide during firing. The same reaction is used to-day 
to make the best ruby glass for signal-lights. 

The next development in the use of copper in 
ceramics came from the Mohammedans in Spain. 
HKastern peoples had invented the ‘‘luster’’ glaze, in 
which a thin film of silver fired with the glaze gave 
a beautiful iridescence to the surface. The Saracens 
adapted copper to this process in place of silver, and 
obtained luster of the rich metallic copper color. Cop- 
per sulphide was used as the paint, and reduction to 
the metal was effected during the firing by applying 
vinegar, ocher, and wood smoke. 

The very beautiful majolica ware was produced in 


310 THE STORY OF COPPER 


Italy during the late middle ages and the Renaissance, 
first in imitation of the Moorish and Chinese ware that 
came into the country in commerce, and then acquir- 
ing an individuality of its own. Famous china, stone- 
ware, and porcelain centers soon appeared through- 
out Kurope. Their products, though differing in 
shape and decoration, were all of the same general 
style of manufacture, painted decoration often in cop- 
per’s blue and green on a white, opaque tin enamel. 

Another new development in pottery, the Wedg- 
wood ware, arose in Kingland in the eighteenth century. 
It differed from its immediate predecessors in being 
unglazed, yet impervious to water. Its geniuses were 
Turner and Wedgwood. In type, the ware is a porce- 
lain body, made from very fine, plastic white clay, and 
mixed with barytes. Color is then introduced in the 
form of those metallic oxides which have always been 
used in ceramics. Clay figures of white or a contrast- 
ing color are molded and pressed on, and united to 
the tinted background by firing. Many of the designs 
are adapted from the charming decorations on Greek 
vases. 

The history of copper salts as decorations in ceramic 
manufacture is about complete. First the colored 
glaze was used, then decoration under a transparent 
glaze, then the combination of painting the body and 
covering it with a tinted transparent glaze. With the 
introduction of opaque white tin glaze, the decoration 
was applied over it. Metallic luster followed. Then 
the potters’ attention turned back to the body of the 
ware, and, for a time, decoration of unglazed ‘‘biseuit”’ 
was developed. Modern china and porcelain quite 


COPPER’S COMPOUNDS 311 


generally have reverted to decorated glazed ware, yet 
no one can assert that entirely new forms of ceramic 
ware may not be in store for potters of the future. 
The colors now in use in this industry were probably 
known also by the ancients. Chief among them are 
cupric oxide, which, though black, gives green and blue 
colors when burned on stoneware, faience, porcelain 
and glass; and cuprous oxide, which is responsible for 
beautiful shades of red in glaze and glass. Cupric 
fluoride is used for blue, and cupric acetate, or verdi- 
gris, for green. Porcelain painting draws on one 
more member of the family, cupric borate. 

Another primitive industry with which copper’s 
compounds have long been associated is textile dyeing. 
Copper salts themselves are of little importance as 
dyes on account of their solubility, but the metal enters 
into calico-printing processes as a mordant in the 
form of subacetate, chloride, chlorate, and sulphate; 
as basic cupric chromate and cupric ammonium sul- 
phate; and also. in its metallic state as part of the 
printing machinery. In Egypt, in Rome, and, since 
medieval times, in Europe, designs were applied to 
cloth by hand from small wooden blocks which had 
taken up a little dye from a moist dye pad. The 
block was alternately coated with dye and pressed 
against the cloth, very much as one uses a rubber- 
stamp. An improved printing block had copper in- 
serts in the face to make it more durable and the 
design sharper. Of course, material dyed in this way 
was very expensive, for its printing was laborious and 
exacting. Printing in several colors was practised, 
although each extra color meant another block and dye- 


312 THE STORY OF COPPER 


pad and additional painstaking work. In the last 
century, when machinery suddenly took upon itself 
the drudgery of the world, one of the most widely 
acclaimed inventions was the calico-printing machine. 
It not only printed at an amazing speed, but was so 
arranged that the dyes and mordants, in the form of 
paste, could be fed to the exact spot where they were 
wanted and many colors could be printed at one time. 
Hence come the chintzes and calicoes of our grand- 
mothers, and, by the same process, the fascinating 
variety of printed cottons and silks in the shops of 
to-day. Copper has played its part in the develop- 
ment of this industry, too, for the little copper-rimmed 
blocks of the hand presses have given place to en- 
graved printing cylinders of that same metal. 

In straight dyeing, copper finds its chief use in 
one of the receipts for black. But a more important 
use for it is as an after-treatment for cotton colored 
with certain classes of dyes, since a bath in copper 
sulphate makes those dyes fast. ‘‘Coppering’’ was 
prescribed in a handbook by the German dye monopoly, 
the Badische Anilin und Soda Fabrik, before the war 
as a necessary process in dyeing the brillant fezzes 
for the Turks. 

The three industries just described as needing 
large quantities of copper’s compounds are among the 
oldest of human arts. Another art, predecessor to the 
modern science of medicine, must take its place in the 
history of uses of copper salts. That art was known 
to its practitioners as ‘‘iatrochemistry.’’ It was a 
more modern, a more intelligent, and a more scientific 
outgrowth of alchemy. The iatrochemists set about 


COPPER’S COMPOUNDS 313 


the systematic study of such chemicals as they knew, 
and were particularly interested in their effect on the 
human body. They were the first in modern times to 
explore the field now known as physiological chemistry. 
Their influence persisted long after their formal 
doctrines were outgrown. One of their ablest suc- 
cessors was Johann Rudolf Glauber, who was born in 
Bavaria in 1604. He, too, was interested in com- 
pounds and their properties, and was the chemical dis- 
coverer of a number of metallic salts, among which 
was copper sulphate. He was not, of course, the 
first human being to see this compound, for it was 
well known to Roman metal-workers, and was de- 
‘ seribed by Dioscorides as pieces ‘‘shaped like dice 
which stick together like grapes.’’ But Glauber pre- 
pared it in a laboratory manner by dissolving copper 
in sulphuric acid, studied its behavior, and, as it were, 
introduced it to lay society. We do not know whether 
the Romans used blue vitriol as a medicine or not. 
We are not certain that Glauber did, but in view of 
his interest in medicinal salts, we may be fairly sure 
that he tried it on somebody. At any rate, after 
Glauber this salt took its place among doctors’ pre- 
scriptions. 

Copper in other forms has also been used medicin- 
ally. Both Dioscorides and Pliny refer to ‘‘flowers of 
copper’’ as a valuable medicine. According to Dios- 
corides, they are formed by pouring cold water upon 
molten copper, whereupon ‘‘the copper spits and. 
throws off the flowers.’’ Pliny has them formed by 
air instead of water: ‘‘The flowers of copper are 
used in medicine; they are made by fusing copper and 


314 THE STORY OF COPPER 


moving it to another furnace, where the rapid blast 
separates it into a thousand particles, which are called 
flowers.’’ He describes two other substances, smega 
and diphrygum, which were also formed as _ by- 
products of copper smelting and used similarly. They 
were probably all the same substance, whatever it may 
have been. 

Modern medicine makes use of verdigris, copper 
acetate, in diseases of the skin, and still uses copper 
sulphate as an astringent and an emetic. Physicians 
to animals also make use of it. The dose for human 
beings is specified as 0.25 gram, with the caution that 
ammonium salts are incompatible with it; the veteri- 
nary prescriptions are similar. Horses get from four 
to eight grams, and cattle from four to twelve. Sheep 
and hogs take about the human dose, 0.3 to 1.3 grams, 
and dogs need only 0.016 to 0.138 gram. Its use in- 
ternally is not free from danger, for all copper salts 
are poisonous to some extent. It is now more com- 
monly used locally as a caustic and antiseptic. 

Although not far removed from medicine and 
hygiene in our thoughts to-day, insecticides are a much 
more recent product of human ingenuity. Man has 
only lately awakened to the fact that he has to fight for 
his very existence, not against horrendous dragons 
nor human foes, but against that part of the earth’s 
population to which he refers scornfully as ‘‘bugs.”’ 
These creatures destroy our food, spoil our crops, kill 
our trees, damage our houses, devour our warm cloth- 
ing, even invade our tissues and produce disease. Our 
most deadly poisons must be drafted into chemical 
warfare against them. The rather slight toxicity of 


COPPER’S COMPOUNDS 315 


copper salts makes them the standard agricultural in- 
secticide, for they will kill harmful insects without in- 
juring the plants or spoiling the food value of their 
fruits. Paris green and Bordeaux mixture are the 
two familiar chemical friends of the farmer. Arsenic 
joins its more deadly properties to copper in Paris 
green, cupric aceto-arsenite, to war on worms and 
larve. Bordeaux mixture is lime, copper sulphate, 
and water, and is the great enemy of caterpillars and 
moths. Other copper salts similar in nature to these 
two are also used for the same purpose: verdigris, 
copper subacetate, cupric arsenite, and cupric am- 
monium sulphate. The ‘‘white disease’’ of grapes is 
treated with cupric fluosilicate. 

Copper sulphate is also death to alge, the small 
green plants that at times have produced an unpleas- 
ant taste in the water of several large cities. Large 
quantities of the salt are needed to remove this taste 
and to kill the bacteria, although only two pounds of 
copper sulphate are used to the million gallons of 
water. Other aquatic troubles are being conquered 
by another copper salt, the oleate. It was recently 
discovered that if fish-nets are cured by impregnating 
them with this salt it discourages even those marine 
pests whose appetite for twine is unaffected by the 
coating of tar usually employed. 

Minerals, of course, are the compounds which we 
find already formed in the earth. We have seen that 
their chief use is as the source of the metal which we 
find so valuable. But some of copper’s ores are so 
beautiful in their bright colors and regular markings 
that they are set apart into a department of mineral- 


316 THE STORY OF COPPER. | 


ogy whose importance varies greatly in people’s minds. 
‘hey are used as gems. A gem is purely an object 
of beauty. It has little intrinsic value. Not all gems 
are mounted by the jeweler, for the mineral enthusiast 
usually makes his own collection of finely crystallized, 
or rare, or beautifully colored specimens whose only 
use is to delight the eye. Almost any one of copper’s 
ores would add interest to such a collection. But the 
lapidary usually cuts and polishes only malachite, the 
carbonate, or, more rarely, its close relative, azurite. 
He has his own standards for judging a mineral’s 
fitness to enter the ranks of jewels. Each of its quali- 
ties of individuality must meet his requirements. 
Color and luster are characteristic properties of great- 
est importance to the gem collector. Hardness not 
only aids the scientist in recognizing minerals but 
determines for the jeweler the wearing qualities of 
those minerals when used as ornaments. Mineralo- 
gists have adopted a series of ten minerals of gradu- 
ated hardness to serve as a scale for measuring this 
property. They are, from the softest to the hardest: 
(1) tale; (2) gypsum; (3) calcite; (4) fluorite; (5) apa- 
tite; (6) orthoclase; (7) quartz; (8) topaz; (9) co- 
rundum, the mineral name for both ruby and sapphire; 
(10) diamond. The mineralogist, to remember the 
seale, takes a leaf from the book of the sure-fire 
memory expert, and makes up the first letters of the 
minerals’ names into the fascinating word ‘‘tagy- 
caflaporquatocodi,’’ but he does not carry samples 
of the ten with him when he goes out prospecting. 
His equipment then for testing hardness consists of 
his finger nail, with a hardness of 2; a copper cent, 


COPPER’S COMPOUNDS mali 


which scratches in Class 3, the blade of his pocket 
knife whose hardness is 5; and, if he expects to en- 
counter objects in the ruby-diamond class, a quartz 
crystal. Each of these standards can scratch all the 
softer ones and can in turn be scratched by those that 
are equal to it or harder than it is. Metallic copper 
will scratch gypsum and calcite, but it is scratched in 
turn by calcite and fluorite. Malachite is a little 
harder, corresponding to 4. For that reason it is not 
a more important gem stone, for the lapidary prefers 
more durable minerals whose hardness is greater 
than 6. Malachite and azurite can be used only where 
not subject to wear. In this country, where most 
gems are made into personal ornaments, these min- 
erals are not as important as in Europe. Before the 
War the beautifully banded malachite from Siberia 
was made up there into vases, boxes, and even objects 
as large as mantels and tables, and was also used in 
mosaics. Opinions about the use of minerals as gems 
differ greatly. Many mineralogists, on the one hand, 
look upon interest in jewels as a regrettable sur- 
vival of barbarism. The opposite extreme is the 
veneration of these shiny baubles for the magic 
powers which superstition has given them. Malachite 
had its share of virtues attributed to it by the an- 
cients, centering chiefly in marvelous.medicinal prop- 
erties. The mere wearing of it was believed to 
ward off dangers and disease. It would make children 
grow and prevent convulsions. If they had colic, they 
had only to swallow some powdered malachite to be- 
come well. But the mineral’s most remarkable power 
was said to be as an anesthetic. The ‘‘Speculum 


318 THE STORY OF COPPER 


Lapidum’’ has it that malachite ‘‘being taken in drink 
or bruised in vinegar and applied to the members that 
are to be cut off and burnt, it makes them so insensible 
that they feel scarce any pain.”’ 

Minor employments of the salts of copper are found 
on every hand. The great electroplating industries 
have the waters of their tanks colored blue by copper 
in solution, for the sulphuric acid which conducts the 
atoms of the metal from anode to cathode turns them 
to copper sulphate on the way. In electrolytic refin- 
ing, the impurities in the crude copper anodes also go 
into solution in the acid, and are not precipitated out 
on the other side, and so the tank water must be drawn 
off from time to time when it grows too impure. ‘This 
liquid is one of the sources of commercial blue vitriol, 
which is one fourth copper. 

The chemist in his laboratory finds a variety of uses 
for the salts of copper. One of the commonest is the 
employment of cupric oxide as a source of oxygen in 
his combustion furnace. A similar use is the separa- 
tion of a gas like oxygen, which will combine with cop- 
per, from one like nitrogen, which will not. To do 
this, the chemist allows the mixture, in the above case 
air, to pass through a hot tube containing fine grains 
of the metal. This is the first step in isolating the 
rare gases of the atmosphere. Copper sulphate’s in- 
sistence upon taking up water to build into the struc- 
ture of its crystals is cleverly used to remove small 
amounts of water from organic liquids in which the 
salt does not dissolve. This is particularly useful in 
the case of alcohol. Absolute, or dry, alcohol is a 
valuable solvent, but it boils at a higher temperature 


COPPER’S COMPOUNDS 319 


than a mixture of 95 per cent. alcohol and 5 per cent. 
water. Ninety-five per cent. alcohol is therefore the 
purest that can be got by distillation. It is shaken 
with quicklime until nearly all the water has been ex- 
tracted; then it is filtered, and some dehydrated cop- 
per sulphate is added to it. This salt is quite colorless. 
The characteristic blue color does not appear until 
it takes up water of crystallization. Alcohol in which 
a fresh sample of anhydrous copper sulphate remains 
white is absolute. One other important reaction de- 
mands copper. It is a test which distinguishes the 
simple sugars like glucose, milk sugar, and the fruit 
sugars from the more complex cane-sugar and from 
starches. Fehling’s solution, which is made of cop- 
per sulphate, acid potassium tartrate, and sodium 
hydroxide is added to a solution of the carbohydrate, 
and the mixture is boiled. The complex substances 
do not change the solution, but the simpler sugars 
break it up, anda precipitate of bright red cuprous 
oxide forms in the blue liquid. The amount of oxide 
formed is a measure of the amount of reducing sugar 
present. A still different occupation of copper in the 
laboratory is as a catalyst, one of those subtle per- 
suaders which the chemist calls in to set a reaction 
going when it will not go for him alone. And there 
are still many more ways in which copper and its com- 
pounds make themselves useful to the chemist, which 
cannot be told. 

Copper salts in great numbers have been used in 
photography on an experimental scale, but their great- 
est uses to man seem to lie in other fields. Cupric 
nitrate is, however, used to some extent in the prepara- 


320 THE STORY OF COPPER 


tion of light-sensitive papers. A few other uses of 
some of copper’s compounds merit some notice, not 
so much for their importance as for the unusual things 
we find them doing. Cupric abietinate, a compound of 
copper and resin, protects wood from insects and de- 
cay. Barnacles are discouraged from taking up their 
abode on ship bottoms by a very similar compound, 
cupric resinate, and also by cupric and cuprous sul- 
phides incorporated in the paint. Fireworks fre- 
quently employ copper carbonate to make their green 
fire, and other copper salts are sold to be sprinkled on 
the fire in the home to remind one of the colors of 
burning driftwood. The salts do not really burn, even 
in fireworks; they volatilize in the flame of other sub- 
stances and give it a green color. But copper phos- 
phide, a relatively unstable compound, can be made to 
do even more spectacular things. Mixed with potas- 
sium and cuprous sulphides, it becomes explosive, and 
may be used as a primer. The mixture is known as 
Abel’s fuse. 

Another unusual use of copper sulphate will delight 
the motorist and highway engineer, since when 3 per 
cent. of this copper salt is added to the usual asphalt 
conerete it seems to keep the road surface from ‘‘run- 
ning’’ when exposed to the heat of the sun in summer. 
The United States Forest Products Laboratory has 
recently found that copper salts improve casein glue, 
not only in stickiness but presumably in color as well, 
since the report speaks of the violet glue which results. 
Sometimes, sad to say, copper salts are even found 
in conspiracies to defraud. Cupric chloride may per- 
haps find mitigating circumstances to excuse its ap- 


COPPER’S COMPOUNDS 321 


pearance as a sympathetic ink, and some people may 
like their white marble dyed blue with cupric fluosili- 
cate, since it is thereby hardened as well, but what can 
we say when we find cupric stearate bronzing plaster 
statues and sedate copper sulphate parading itself as 
a hair-dye? 


CHAPTER XV 
THE BRASS AND BRONZE OF WAR 


Important as copper is in peace, it is more important 
in war. A man can not be killed in an up-to-date man- 
ner without copper. Supplies of copper are as neces- 
sary as drafts of men, and the nation without suf- 
ficient brass or bronze with which to equip its men 
finds itself in an unpleasant predicament. ‘‘The na- 
tion that goes to war without a good stock of copper is 
worse off than it would be without a board of strat- 
egy,’’ 1t has been said. This is indeed true; wars 
have been won despite a surprising lack of military 
sagacity, but no conflict of any consequence since the 
fashioning of the first copper battle-ax has occurred 
without red metal fighting in some way on both sides. 
The rations of war are copper, brass, and bronze as 
well as iron, coal-tar, wool, wheat, and gasolene. 

Long before America entered the World War, long 
before the war clouds over Europe broke in 1914, cop- 
per was in the service. In arsenals, in munitions, in 
uniforms, in the products of peace that can be applied 
to war, copper was stored, purposely or unintention- 
ally, ready to be called upon in the event of war. 
When the war began in Kurope the demand for cop- 
per was temporarily slackened by interference with 
normal trade, but only a few months were required 


before the greediness of war and its taste for red 
322 


BRASS AND BRONZE OF WAR 323 


metal began to show itself. America began to get 
munition orders; equipment and material for modern 
war meant large quantities of copper. 

Then at last April, 1917, came, and America entered 
the war. The copper industry virtually enlisted it- 
self along with the youth of the country. Its peace- 
time jobs had to be left to others of the metallic fam- 
ily. As a president of a large copper company has 
said: 


I sometimes wonder how many people understand the fields 
which copper and brass abandoned in a few hours in order 
to do its part in war service. In a score of industries rep- 
resenting an annual consumption of copper and copper al- 
loys running into hundreds of millions of pounds, an almost 
disastrous condition was created. There was no copper for 
them. The government needed it all and none was disposed 
to question its right to all that could be produced. 


That sacrifice was made, and all that was in copper 
was injected into the war. New mines were opened, 
new smelters were built, and night and day the mines 
and reduction plants poured forth the red metal that 
in war is more precious than gold. Between the pre- 
war year of 1913 and the peak war year of 1918 cop- 
per production in the United States increased by more 
than one half, and throughout the world, in warring 
as well as neutral countries, production was so much 
stimulated that the world total was increased by about 
the same percentage. This metal went through the re- 
fineries at a greater rate than ever before. In the mu- 
nition factories most of this copper was used. Nearly 
all of the metal in the small arms ammunition that 


THE STORY OF COPPER 


324 


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(explosive) 


sive charge 


‘plo 


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Copper band or 

rotating band 
Cartridge case 
(grown brass) 


SSS . 


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“‘America’s Munitions’’ 


From 


SKETCH SHOWING THE WAY IN WHICH COPPER AND BRASS ARE 


HIGH EXPLOSIVE NOSE, FUSE TYPE 


’ 


SHELL 


USED IN A 75mm, 


BRASS AND BRONZE OF WAR 395 


plays such an important part in the fighting is com- 
posed principally of alloys of copper, and cases for 
artillery shells are made of brass. Each steel pro- 
jectile of big caliber is accompanied by a band of cop- 
per in its flight toward the enemy. 

Take the .30-caliber service cartridge that is the 
mainstay of the American army. Billions of these 
were made during the war, and the peace-time produc- 
tion was 100,000,000 a year. The bullet is incased in 
a heavy metal jacket of cupro-nickel, an alloy of about 
85 per cent. copper and 15 per cent. nickel. This 
combination is used instead of steel because very hard 
metal will wear out the delicate rifling of the gun- 
barrels, and iron-containing metals will rust and be- 
come useless. Cupro-nickel is not hard enough to 
damage the rifling excessively and yet is sufficiently 
strong and hard to keep the interior slug of hardened 
lead from deforming and running out of its case. 
Germany, pressed for red metal that it cannot mine 
at home, used a bullet with sheet-steel jacket, but 
even this attempt to do without copper entirely failed, 
for the coat of copper had to be added to the bullet’s 
exterior to preserve it from rust and soften its con- 
tact with the barrel. So fast was the manufacture of 
munitions draining America’s copper supplies that 
army engineers experimented and perfected a similar 
steel copper-coated bullet, that would have been put 
into production if cupro-nickel supplies had failed. 
No satisfactory substitute for brass cartridge-cases 
and shells has been found. Experiments have been 
made with steel, but, in addition to being liable to 
rust, they are too expensive. The shell-cases of both 


326 THE STORY OF COPPER 


the rifle, machine-gun, and pistol ammunition and of 
larger artillery rounds are made of a brass contain- 
ing about 70 per cent. copper. Brass is used for this 
powder container because pure copper, while tough, 
has not enough resiliency to spring back to the orig- 
inal form after being thrust against the chamber walls 
of the rifle by the high gas pressure developed in the 
firing. The chamber pressure of a military rifle is 
often higher than 50,000 pounds to the square inch. 
If the case does not spring back on account of being 
too soft, or if the rifle chamber is the least bit pitted, 
the shell-cases will be smeared upon the chamber walls 
and can not be extracted easily to give way to a loaded 
shell. And if the shell is too hard and brittle it is 
likely to split at the neck or break off at the base. 
For these reasons the brass shells must be manufac- 
tured with great care; the temper and gage of the fin- 
ished case is very important. Cartridges used on the 
rifle-ranges in peace and often those used in actual 
battle are salvaged and used many times over. Speci- 
fications for United States cartridges require that 
they stand twenty reloadings without failure. This 
results in economy, as the pre-war cost of an army 
cartridge complete was 21% cents, and the brass case 
accounted for 114 cents of that amount. 

Every portion of the complete cartridge except the 
powder charge contains copper. The primer cup and 
the anvil, upon which the firing-pin falls as the first 
act in the series of episodes that occur in firing a rifle, 
are made of copper. Even the clip which holds five 
cartridges together so that they can be handled easily 
and loaded quickly in the rifle is stamped out of sheet- 


BRASS AND BRONZE OF WAR oot 


brass. In the manufacture of a cartridge-case flat 
disks are stamped out of sheet-brass as the first opera- 
tion; the next operation consists of forming a cup of 
the disk. In the successive operations the cup is 
gradually drawn out into a cylinder, and the cylinder 
in the final operation is ‘‘necked down’? to suit par- 
ticular requirements. After each drawing process the 
case must be annealed, as the mechanical work done 
on the case during the draw makes it hard and brit- 
tle. As an intermediate step during the drawing 
operations, the head is formed from the thick metal 
left in the base. | 

When the war began only the ordinary type of bul- 
let that has been described was standard for Amer- 
ican ammunition. New methods of fighting brought 
the need for new kinds of bullets. An armor-piercing 
bullet was perfected by replacing most of the interior 
slug of lead with very hard steel. A tracer that can 
be followed by the eye in the brightest sunshine was 
made by partly filling the cupro-nickel jacket with a 
mixture of barium peroxide and magnesium. For in- 
cendiary purposes, phosphorus was loaded into the 
jacket in such a way as to bestrew itself over the land- 
scape when fired. As in the common service-bullet, 
the copper-containing jacket is an essential in all these 
new forms. 

For the service-rifle and ordinary machine-gun, the 
.30-caliber cartridge was used by our forces, but for 
automatic pistols and revolvers .45-caliber ammuni- 
tion was made. Need for machine-guns shooting 
large bullets was felt, and some eleven-millimeter am- 
munition, about half an inch, was made for them. 


328 THE STORY OF COPPER 


But in the manufacture of these cartridges the 
methods of .30-caliber ammunition were used and cop- 
per played the same important part. 

It is estimated that the ordinary rifle cartridge will 
contain from 23,000 to 28,000 pounds of copper in a 
million cartridges, depending upon the make of rifle.. 
During the nineteen months of warfare the American 
production of machine-gun and rifle ammunition was 
2,879,148,000 rounds, and during that period England 
produced 3,486,127,000 rounds, and France 2,983,675,- 
000. It is estimated that these cartridges alone, ex- 
cluding any of the other war uses of copper and the 
cartridges manufactured earlier and after the war, 
consumed about 243,000,000 pounds of copper, nearly 
one fourth of the toal domestic consumption of copper 
in this country in 1920. 

The cartridges for the smaller sizes of artillery are 
simply overgrown rifle-cartridges in their appearance 
and construction. The bullet of copper alloy is re- 
placed with a steel shell, but copper still guides this 
projectile to its mark. A ring of copper encircles the 
shell near its base. This not only allows it to follow 
the rifling of the gun and acquire the twirl that keeps 
it straight in its flight, but it keeps the gases of the 
explosion from creeping out past the shell to impede 
rather than help its travel. These copper rotating 
bands will average two and a half to three pounds per 
shell. When artillery must fire quickly and the 
charge is small enough to be carried in one package, 
the same sort of device for inserting powder and pro- 
jectile into the gun is used as for the rifle. The larger 
cartridge-case is also made of brass; the principal 


Courtesy of Ordnance Department, U. S. Army 


EVOLUTION OF A RIFLE CARTRIDGE 


View showing successive stages in the manufacture of primer, case, bullet, and 
clip for .30 caliber U. S. Army rifle ammunition. All of the parts contain copper. 
The top row shows the development of the primer cup and anvil.. The second and 
third show the development in the manufacture of the cartridge-case. The fourth 
row shows the development of the bullet. Completed cartridges are shown in the 
next row, and the bottom row illustrates the steps in the manufacture of the brass 
clip that holds the cartridges together. 


U. S. Signal Corps Photo 
A DUMP OF EMPTY .75’S 


Each one of these brass shell-cases has discharged its powder and shell in actual 
warfare in France. 


DISTINGUISHED SERVICE CROSS 


A medal of bronze, symbolizing the high- 
est honor bestowed by the United States 
Government exclusively for bravery on the 
battle-field. 


BRASS AND BRONZE OF WAR 329 


difference is that the rifle cartridge-case weighs a 
few ounces and the gun shell weighs pounds. The 
following list of weights of brass shells will give some 
idea of the quantity of copper used in artillery am- 
munition: 


Caliber in Length of Case Weight of Case 


Millimeters in Inches in Pounds 
3-inch field-gun 75.29 6.220 Leb. 2552 0%. 
3.2-inch, U. S. army 81.9 13.300 4° lb. 2407. 
4-inch 100.4 28.575 LOSI 3s Oz: 
4,72-inch 119. 34.840 Lotlbae $2.07. 
5-inch 126.2 34.875 187 1b. Ais Zz, 
6-inch 157.2 41.60 28 lb. 134 oz. 


For every gun in action there must be piles of 
loaded shells. The famous seventy-five millimeter 
gun can open up with a prolonged fire at the rate of 
one shell every ten seconds; in case of necessity one 
shot every three seconds can be achieved. Tons of 
brass must back up each artillery battery. 

In many ways copper enters into implements of war 
other than ordnance. One of the American achieve- 
ments of the World War was the radio telephone 
through which aviator could talk to aviator or to a 
ground station. As with the many radio sets erected 
for pleasure to-day, without copper, radio in war 
would have been impossible. Miles of telephone and 
telegraph wire went to France with all their copper- 
containing accessories. The green color of rockets 
and the other signal pyrotechnics of the battle-front is 
given by salts of copper. In the ranks of the Signal 
Corps in France there were 15,000 pigeons who suc- 
ceeded in delivering 95 per cent. of the war messages 
entrusted to them, attached to their legs in a tiny 


330 THE STORY OF COPPER 


capsule. Bands of pure copper held these messages 
securely to the birds’ legs after aluminum had been 
found to be too easily broken. Copper enters into 
the manufacture of nearly every major article used 
in warfare; it formed parts of the bearings, fuel, and 
ignition systems of the Liberty aviation engine and 
the horse-replacing auto-trucks; it conveys electricity 
to the great search-lights; and the latest type of trench 
knife designed by the A. EK. F., like the knives of old, 
had a bronze hilt. Military locomotives utilized red 
metal for their fire-boxes; doughboys wore identifica- 
tion-tags made of a copper alloy. Brass buttons once 
were symbolic of the military. In recent years the 
shiny brass has been dulled to bronze for fear that 
its reflection would draw fire and death, but copper 
still adorns the uniforms. In the field the dull busi- 
nesslike insignia that symbolizes the authority of 
officers are made of metal containing copper; in hap- 
pier times the ‘‘gold’’ braid of full dress that enhances 
a military ball is really spun brass or bronze. In the 
war-ships at sea, in the supply-ships that serve the 
fighting forces, in all the equipment of the great civ- 
ilian army at home, vastly outnumbering the fighting 
forces, red metal plays its part in war. 

Even in peace, when the war has been won and the 
country sickens at the thought of hostilities, more 
than twenty million pounds of copper are being used 
in ammunition each year. Shot-gun shells of ordi- 
nary manufacture are made of paper with a brass 
end or cap, about five million such cartridges are made 
each day in the United States alone. Numerous other 
cartridges, ranging from the small yet effective .22- 


{ 


BRASS AND BRONZE OF WAR 331 


caliber B.B. cap to the sporting counterpart of the 
high-power military rifle cartridge loaded for bear, 
are added to the total. 

The United States had copper enough for the war— 
not a superfluity, but sufficient for actual needs and 
a reserve for the future if the war had been prolonged. 
America’s copper mines and smelters produced as 
never before and fed the armies of our allies as well 
as our own. America’s resources may be visualized 
from the fact that after the War the Government was 
able to turn back into commerce about 100,000,000 
pounds of copper and brass that had been purchased 
for war purposes. This was nearly equivalent to one 
normal year’s consumption of the munition industries 
of this country. Still you may read in the technical 
periodicals of the War Department offerings of heavy 
tonnages of copper and brass to be sold by bids. The 
qualities are still sizable, as typical items show: 862,- 
107 pounds copper ten-inch rotating bands; 396,305 
pounds copper eight-inch rotating bands. 

Copper in Germany during the war has quite a dif- 
ferent story to tell. The Central Powers have always 
been lovers of copper and copper products. Germany 
has held a unique place among the world’s copper 
consumers, as her per capita consumption exceeded all 
others and her production was very low. A great 
variety of copper-containing objects were manufac- 
tured and used, and the most popular type of build- 
ing front was sheet copper or bronze. Now Germany 
and Austria are virtually denuded of all removable 
copper, brass, and bronze; it has been sacrificed to 
war. At the outbreak of hostilities Germany held 


332 THE STORY OF COPPER 


enormous stocks of copper, and to these the Govern- 
ment added within three days all the available copper 
in the neutral countries of Europe, buying at the in- 
stigation of the great German organization, the Allge- 
meine Hlektricitats-Gesellschaft. First of all, Ger- 
many ran short of nickel and platinum, and then came 
a shortage of copper and brass, which grew more and 
more acute as the war progressed. The war lords 
requisitioned all the copper that they could lay their 
hands on. Jitchen pots and pans, faucets, door han- 
dles and knobs, locks, brass fixtures of all sorts, mor- 
tars and pestles used in the home for crushing sugar 
and spices, ornaments, statues, locomotive fire-boxes, 
and even church-bells were seized and melted down to 
make shells and bullets. Museum relics and scraps 
were treated alike. From the church-bells alone 
30,000,000 to 40,000,000 pounds of copper were ob- 
tained, and the bronze bells were replaced with steel 
ones, which, however, are proving unsatisfactory, 
especially in tone. The only copper roofing that re- 
mains to-day in either Germany or Austria is that 
on domes, as copper sheets were not removed from 
curved roofs because of the labor and expense in- 
volved in replacing them. Copper roofs for public 
buildings were very popular in Middle Europe be- 
fore the war and were used so extensively that the 
German militarists are suspected of having availed 
themselves of this use as a means of quietly storing 
copper for the war to come. By its requisitions of 
copper and its alloys, it is estimated that the German 
Government secured 300,000,000 to 400,000,000 pounds 
of copper within its own territory. And added to this 


{ 


BRASS AND BRONZE OF WAR 333 


immense amount were the quantities seized in Poland, 
Russia, Belgium, Northern France, and other terri- 
tory invaded by Germany. Germany’s crying need 
for copper can be realized when it is recalled that part 
of the return cargo of the transatlantic submarine, the 
Deutschland, was red metal. 
Copper has always been a favorite material in 
man’s warfare. As his earliest metal it supplanted 
stone cudgel and flaked arrow-heads. As a component 
of bronze it was a favorite material for cutting and 
piercing weapons long after the softer iron had be- 
come common in the ancient household. Later in his- 
tory copper-containing metal was used defensively as 
well as offensively; shields and armor were made of 
brass and bronze as a foil to bronze spears and swords. 
Then, when hundreds of years later the age of chiv- 
alry with its metal-clad knights and chargers was in its 
greatest glory, brass and bronze cannons came into 
fashion along with gunpowder. Long-range fighting 
that resulted from the use of ordnance forced troops to 
move quickly from place to place, and, as armor ham- 
pered speedy travel, it was abandoned for this reason 
rather than for lack of ability to withstand gun-fire. 
In time, with the growth of metallurgy and mechanical 
skill, brass and bronze were abandoned as material for 
guns, but during the same transition muzzle-loaders 
gave way to faster firing breech-loaders. Some better 
way of loading than the old method of ramming home 
each component of the charges separately was needed, 
and to answer this need the cartridge of brass was de- 
vised. To-day billions of brass shells, some of them 
larger than the medieval brass cannons out of which 


334 THE STORY OF COPPER 


they have grown, are manufactured and used in war- 
fare. 

Archeologists have dug up much of the past of the 
early people on this earth, and it is interesting to note 
that the most impressive and best-preserved remains 
of ancient life relate to strife. The majority of the 
implements preserved are weapons, and the historical 
legends that were passed from mouth to mouth, from 
generation to generation, report warfare more clearly 
and with more enthusiasm than the more peaceful pur- 
suits of every-day life. One reason for this is that 
the ax that was used as a weapon was also used in 
pursuit of an animal that could be cooked for supper. 
The American Indian living in the copper age used 
his copper-tipped spear to kill both antagonistic tribes- 
men and the buffalo that provided him with meat and 
clothing. Thus, if the hostile side of man has been 
given prominence in recorded history, it is partly be- 
cause his fighting and his living were so intimately 
mixed. 

It has already been explained how copper imple- 
ments and weapons had a tendency to take on the 
same shapes as the stone ones they gradually super- 
seded. As the next step, tin joined copper and pro- 
duced harder, more durable weapons. Later, iron 
appeared, but it was soft and inferior to bronze un- 
til the secret of steel was learned. There was a long 
transition period, with ferrous weapons gradually 
gaining. : 

In the Homeric poems, bronze is the most fre- 
quently mentioned metal. The warrior of prehistoric 
Greece, described in these legends, wore, when in full 


{ 


BRASS AND BRONZE OF WAR 335 


armor, a shield, greaves, band, belt, tunic, helmet, 
breastplate, and sword. As the poem tells us: 


He for Ajax framed the shield 
With hides of pampered bullocks in seven folds, 
And an eighth fold of brass,—the outside fold. 


Huge shields were composed of layers of ox-hide 
overlaid with bronze to make them more resistant to 
showers of missiles. Here, as in most of the early 
folklore, what is translated as brass is not a mixture 
of copper and zinc but in reality the mixture of cop- 
per and tin that we call bronze. Protecting the legs 
of the Homeric warrior were legging-like greaves, and 
while these were generally made of hide there is ref- 
erence in the poem to warriors greaved with bronze. 
The belt was also metal-plated, and it is generally be- 
lieved that the breastplate in many cases was of 
bronze. It is probable that early armor was used by 
the fighting man that Homer describes and that they 
wore bronze corselets, an improved form of stiffened 
shirt. Moreover, copper-containing metal was used 
not alone for personal armor but for protection of 
horses and chariots and of the material for weapons, 
as the following passages relate: 


O warriors Ajax, leaders of the Greeks 
In brazen armor. 


His horses, and his chariot bright with brass. 


Two brazen-pointed javelins he defied 
To mortal fight the bravest of the Greeks. 


336 THE STORY OF COPPER 


And in the Bible there is also evidence of bronze 
armor being used (again the brass should really be 
translated bronze) : 


And Saul clad David with his apparel, and he put a helmet 
of brass upon his head, and he clad him with a coat of mail. 


During the early historical era of Greece and Rome, 
the armament of men and the form of their weapons 
did not differ radically from those of the legendary 
period that preceded these civilizations. In the lat- 
ter portions of the era iron weapons were used exten- 
sively and the same metal was beginning to be used for 
bodily protection. For hundreds of years after 
Cesar had led his legions, armor and personal com- 
bat dominated warfare. Suits of mail and plates of 
metal were used as late as the sixteenth century. 
Some armor was made of brass and bronze, but most 
of it, especially the elaborate suits of the later years, 
was fashioned of steel. About 1300, cannons appeared 
in Kurope, and the course of warfare began to change, 
although it took years for firearms to replace the 
older methods of fighting and, as our recent dose of 
trench fighting shows us, hand-to-hand fighting will 
probably always persist. 

Bronze and wrought iron vied with each other as 
the material for guns from early in the fourteenth 
century when cannons came into vogue until very re- 
cent years when modern methods of metallurgy and 
military tactics have made possible steel rifled guns 
and the subsidiary brass cartridges. Early in the 


BRASS AND BRONZE OF WAR 337 


use of guns large pieces of bronze were built and used; 
some of these weighed as much as eighteen tons. It 
was only when improved design of ordnance coupled 
with better metal allowed the use of steel in guns of 
large caliber that bronze was no longer used for field- 
pieces and larger guns of cast-iron were superseded. 
Though bronze cannons have remained only in mu- 
seums, the alloy from which they were most frequently 
made is still called gun-metal. 

Peace-loving people of all ages have had a tendency 
to abhor the material of war. Poison gas has recently 
had its share of hate directed at it, and curses have 
been called down upon steel for making modern war- 
fare possible. In Agricola’s time (1550) people cursed 
metals and mining for the horrors of war. Iron had 
its evils, they believed, but Agricola in these words 
tells how they regarded copper: ‘‘Because muskets 
are nowadays rarely made of iron, and the large ones 
never, but of a certain mixture of copper and tin, they 
confer more maledictions on copper and tin than on 
iron.’’ 

Years after the last big battle has been fought, 
when copper is no longer used for militant purposes, 
when fertile fields have grown over the scene of war, 
when peace is at its noonday, a farmer will be re- 
minded of war when he finds in his tractor furrow a 
dirt-filled brass cartridge. And when the light of the 
sun begins to dim and he chugs homeward he may read 
in everlasting bronze, the inscription: 


IN MEMORIAM, FOR THOSE WHO FOUGHT AND 
WON. 


338 THE STORY OF COPPER 


Hardly a village nowadays lacks a military me- 
morial, though it be only a plain bronze plaque let- 
tered with the names of the youth of the neighborhood 
who have died in the service. More pretentious me- 
morials, including a statue of a group, perhaps, are 
often flanked with cannons of bronze, remnants of an 
earlier war. Contrasting with the rust of the steel 
implements of later, more civilized wars, these older 
guns take on the beauty of bronze and vie with the 
memorial itself. Thousands of statues commemorat- 
ing a great soldier in war, in civil strife, or in man’s 
battle with his peaceful problems are scattered over 
this country. The beauty and permanence of copper 
has caused the overwhelming selection of bronze as 
the material through which veneration is expressed. 
In Washington the great President who saw the birth 
of the Union is commemorated by a tall marble shaft; 
facing it there is the magnificent memorial to the 
Presidential commander-in-chief during the struggle 
that kept the Union intact. A gigantic Lincoln looks 
kindly down from the center of the classic rectangle; 
his historic addresses are lettered for all time in 
bronze. Far above, blending harmoniously with the 
mural paintings, are six huge bronze beams, stayed 
with bronze. Hight massive bronze doors provide the 
entrance to the memorial, and stairways of the same 
metal lead to the memento rooms. ‘T'en tons of copper 
in flashings and cornice promise to protect faithfully 
the memorial for all time, and fulfil the inscribed 
promise that memory of Lincoln will be enshrined 
there forever. | 

Swords may be beaten into plowshares only in a 


BRASS AND BRONZE OF WAR 339 


figurative sense nowadays, but copper rotating-bands 
for shells are melted down and turned to peaceful uses. 
They and the other copper of war have fittingly been 
used as the metal for memorials, and the bronze can- 
nons of the past, in addition to serving themselves, 
have entered the mold of the military leader who di- 
rected them. If bronze can memorialize war, it can 
glorify peace and good will between nations. The 
famous bronze ‘‘Cock of Jemappes,’’ a shaft on Bel- 
gian soil, commemorates a French victory over a 
German enemy. No statue was torn down more 
quickly and cast into the munitions melting-pot than 
this reminder of defeat in 1792 when the Germans in- 
vaded Belgium during the war. Now the Gallic cock 
has been replaced as the symbol of Franco-Belgian 
friendship strengthened by alliance during the war. 
When the troop ships carrying the returning A. E. F. 
approached New York Harbor, one of the most wel- 
come sights was the Goddess of Liberty, towering 150 
feet in pure copper, the friendly gift of France to 
America. 

The living, the rank and file as well as the officers, 
are honored for heroic deeds and services in war. 
The highest honor that the United States Government 
bestows upon its soldiers exclusively for acts of 
heroism in battle is the Distinguished Service Cross, 
struck in bronze. In virtually every army fighting in 
the World War the prized decoration for heroism in 
the face of the enemy was made of the same copper- 
containing metal. There was one notable exception 
—the Iron Cross. To-day few wear the khaki; the 
soldiers who came back are in civies. In their coat 


340 THE STORY OF COPPER 


lapels they wear the decoration awarded to all who 
wore the uniform, a bronze service-button. There is 
another age of heroes, with dwindling ranks, formed 
at least once a year, and they too wear a little copper 
badge of service. We cheer them as they pass on 
Memorial day; we see them as W. P. F. Ferguson has 
recorded in these lines in the Franklin, Pa., ‘‘News 
Herald’’: 


He is bowed and old to-day 
And goes limping down the way, 
With the little copper button on his breast; 
And few notice as he goes, 
And few think, of even those, 
Of the days when he went marching with the best. 


But that little copper thing, 
If you pause, will mem’ries bring 
Of what ’s proudly writ upon a fadeless page, 
How his valor and his truth, 
In his far-off days of youth 
Wrought the mighty deeds that glorified the age. 


CHAPTER XVI 
BRONZE BEAUTY 


Throughout the history of the world, whenever man 
has become master of any material, he has used it to 
make objects of beauty. It is not surprising, when we 
consider the intrinsic merits of the metals we are con- 
sidering, that copper and bronze have always been 
favorite mediums for the production of works of art. 
Their history is the history of art itself. 

The term Art has come to have, for us of to-day, a 
peculiar connotation. By an unhappy combination of 
circumstances we have divorced art and utility in our 
thoughts. According to our natures, we either praise 
one thing as ‘‘practical’’ and deride a second as 
‘‘artistic,’’? or we reverence the second as ‘‘esthetic’’ 
and damn the first as ‘‘materialistic.’’ Ancient Greece 
is universally looked back to as the fount of beauty and 
the golden age of Art. But were you to draw the line, 
as we draw it to-day, between life and art when talk- 
ing to a cultivated citizen of ancient Athens, he would 
be at a loss to understand your point of view. 

Perhaps the greatest secret of the vigorous art 
works of early peoples was their necessity. The ex- 
ploits of their gods and heroes must be kept ever fresh 
in the minds of the devoted worshipers, in an age when 
reading and writing were among the most difficult of 
the arts. The religious significance of early art works 


must be constantly borne in mind, though it does not 
341 


342 THE STORY OF COPPER 


account for the whole story of the artistic rise and 
decadence of nations. 

A certain instinctive love of beauty is part of the 
mental, or, if you will, spiritual make-up of the human 
race. It shows itself in many ways. One person may 
find a thrilling sense of satisfaction in a spectacular 
sunset, another in a lovely gown. One will delight in 
a delicately wrought bit of filigree jewelry, another 
in the solid mass of a modern sky-seraper. The earli- 
est metal-worker doubtless felt as keen a sense of 
artistic triumph when he turned out a good copper 
blade as does a modern sculptor over a beautiful 
representation of the human form. In the main, we 
like things smooth, symmetrical, and colorful, relieved 
from monotony by interesting and unexpected detail, 
and nicely balanced between the severe and the fussy. 

The savages who made the earliest copper and 
bronze implements might have used mere chunks of 
the metal with a rough cutting edge pounded on one 
side. Instead, we find that as soon as they began to 
master this new material they set about improving and 
beautifying their implements. They made them in 
regular shapes, they smoothed and polished them, and 
they began to decorate them. At first they used 
geometrical designs that they made up out of their 
heads. For a long time they advanced no further; 
then suddenly they seem to have become aware that 
they could copy the things which they saw around 
them. We shall refer now to no one people, for the 
progress of all ran along the same groove. Some 
went further than others before calamity or decadence 
overtook them, but the stages of development are 


BRONZE BEAUTY 343 


virtually the same for all. The first objects whose 
pictures man drew were those of animals. He took a 
very vital interest in them, for they furnished him 
food, clothing, and shelter. He watched them very 
closely and was able to reproduce their movements 
with extraordinary exactness. It is said that the posi- 
tion of the feet in some of the drawings of galloping 
animals in the caves of France have never been used 
since in artists’ pictures but have been shown by 
modern slow-motion pictures to have been correctly 
observed and portrayed. Plants did not interest man 
for a very long time after he had mastered the 
anatomy of the animals, and his fellow-men were taken 
so much for granted that it did not occur to him until 
still later to make their likenesses. That this order 
was not due to superstition is indicated by the fact 
that children, if left to themselves, usually draw their 
surroundings in the same sequence. 

But man’s first drawings, no matter how crude they 
might seem to us, must have appeared very wonderful 
to the childlike contemporaries of the earliest artists, 
and the belief soon arose that considerable magic 
resided in the likeness of an animal or person. It was 
unlucky for you if any one possessed your image, but 
lucky for him, for he had you in his power. This 
superstition is believed to be the reason for those 
marvelous animal pictures, painted with only the 
naturally occurring pigments in the dark recesses of 
the caves of France and Spain, whose artists already 
possessed wonderful skill although they lived so far 
before the dawn of history that we know them only by 
these works and a few fossil bones. Artists, indeed, 


344 THH STORY OF COPPER 


they were, for they portrayed their animals in nearly 
every style of technique known to us at present—draw- 
ing, painting, carving, and sculpture. Of the import- 
ant branches of art, only architecture was yet undis- 
covered. 

From a picture or a statue used to charm food 
animals to one’s traps, the transition to the worship 
of the representation, and then of the animal itself, is 
easy, even though it may have taken many forgetful 
generations. At the same time, as the savage’s life 
grew less hazardous and more comfortable, he began 
to cease thinking of the world as an evil place. In- 
stead of the devils with which his imagination had 
peopled it, he began to put gods who were friendly 
to him and his enterprises. His new gods were much 
like himself, but were still associated in his thoughts 
with the older creations of the tribal mind. 

It is very likely that the monstrous half-animal 
divinities of Egypt originated in some such fashion. 
The halo of ancient custom hung around them, so that 
their worshipers saw them as symbols rather than in 
their hideous reality. Tribes guarded the images of 
their gods in the belief that their loss meant the loss 
of the protection of those divinities. Generals knew 
that the surest way to destroy the enemy’s morale was 
to capture his gods. The tribal images were usually 
carved from great stones or from the trunk of a tree, 
but soon the custom grew up of individuals carrying 
small statuettes of the gods about with them. LHarly 
bronze figures of this sort have been found in excava- 
tions of Assyria and Babylonia. ‘They are but a few 
inches long, and terminate in a spike which could be - 


BRONZE BEAUTY 345 


stuck into the ground. How secure from harm a be- 
nighted traveler would feel, surrounded while he slept 
by a picket-fence of protecting divinities! 

Next after depicting the likenesses of the gods, the 
sculptors and painters turned to representations of 
the rulers, who, their subjects were led to believe, were 
closely related to the gods themselves. Assyrian 
armies carried a corps of sculptors and decorators to 
carve the story of the king’s exploits on the precipices 
of the mountains along their routes. The Assyrians 
and Babylonians excelled in relief work in metal as 
well, and made beautiful plaques, dishes, and even 
doors, but their metal experience did not include the 
casting of large figures. Their rivals, the Egyptians, 
developed metal-work to a greater extent. 

Egypt was in its prime around the sixth century 
B.c. It was a rich country. Its fertile agricultural 
areas along the Nile supported cities as complex and 
as wonderful for their time as any modern metropolis. 
Its people were gay and sophisticated. In religion, 
always an important part of Egyptian life, they had 
broken away from the earlier sun worship, and fol- 
lowed strange cults marked by elaborate ritual. 
Prominent among these was the cult of the dead, which 
is responsible for the mummifying of bodies and the 
construction of elaborate tombs for the important 
members of society. A prominent feature of this 
system of rites was the erection of a stone or bronze 
statue of the deceased which should serve as a part- 
time home for his soul. A sort of reception-room was 
built in front of the tomb, and the statue was set up 
there in state and received visits and presents from 


346 THE STORY OF COPPER 


the relatives and friends of the dead man whose proxy 
it was. The houses of the living were thought of only 
as temporary dwelling-places; the tomb was the per- 
manent home. Therefore its occupant must be made 
as comfortable as possible. But it was, in the nature 
of things, impossible to keep the tomb stocked with 
provisions throughout eternity, and so a very childish 
device of make-believe was adopted. The walls of the 
tomb’s ante-chamber were carefully decorated with 
pictures of everything that the comfort of the soul 
might demand. Flocks of sheep were drawn there, 
and then the picture of a butcher killing a sheep, so 
that the spirit’s mutton supply should always be 
fresh; fields of grain were pictured, and so on. It may 
be remarked here that no responsibility was felt by 
society for the souls of those who could not afford 
the expensive burial rites. Their poor carcasses were 
flung into a trench and covered with a few shovelfuls 
of earth, and their spirits left to fend for themselves. 

This is the background for Kgypt’s art. Sculptors 
and painters were in demand by three classes of em- 
ployers: the priests, to decorate the temples; the king, 
to extol his greatness; and those who could afford it, 
to provide for the future welfare of their deceased 
relatives. The last two offered opportunities for the 
development of art. 

The best works date from this period or earlier. 
Decorated metal utensils are common, and a number 
of statues have been found. The figures of two scribes 
are well-known examples of statues made of bronze. 
One of them sits cross-legged on the ground, ready to 
take his pen in hand and write from his master’s dicta- 


BRONZE BEAUTY. 347 


tion. There is nothing tense in his attitude, for he is 
a middle-aged man, and his muscles have become 
flabby through years spent in a sedentary occupation, 
but the attitude of waiting is written all over him. His 
bright eyes, made of a porcelain-like enamel in black 
and white and fitted between his bronze lids, stare at 
one with a lifelike expression. The character of the 
subject is remarkably well portrayed. The other 
scribe—it only happens that both figures are of the 
same subject—has just surrendered his tablet to the 
master for inspection. With a polite smile on his lips 
and anxiety in his eyes, he hopes that the work will 
please, for he is in for a flogging if it does not. It 
probably will not, for this scribe is decidedly less 
intelligent than the other, but so pitiful is the figure 
that, even while we classify him as a moron, we hope 
the master was not too hard on him—so many cen- 
turies ago. This was Egyptian art at its greatest. 
Not many of its works attain this excellence. 

The Hgyptian metal-workers had not reached com- 
plete mastery over bronze. The face, hands, and feet 
were solid bronze, and cast. The rest of the body was 
hollow, beaten out of sheet-metal and shaped round 
over cores of meaner material. All the parts were then 
carefully matched, and joined by riveting or brazing. 

The freedom of attitude and expression shown by 
some of the statues and a few drawings and reliefs 
must have resulted from work under exceptionally 
favorable conditions. They could not have been 
mortuary statues, for those were bound by propriety 
to a stiff posture. Still less could such natural work 
be done for the temples. 


348 THE STORY OF COPPER 


The temple decorations, hampered by convention, 
degenerated with the religion. Much earlier than the 
sixth century B.c., when the population was largely 
agricultural and the pyramids were relatively new, the 
religion of Egypt—or at least the chief religion 
—was pure sun-worship, and its priests scientific as- 
tronomers. ‘They were the ones who painted the ceil- 
ings of the temples with azurite, the blue copper ore, 
to represent the heavens, and set in their places the 
constellations in five-pointed stars of yellow paint. 
The entrances of the temples faced the east, where 
the first rays of the rising sun could shine through 
arch, gateway, and door into the inner shrine and strike 
the jeweled breastplate of the high priest into flash- 
ing color, a symbol to the worshipers that their god 
was among them. As the country grew richer and 
wiser, many strange practices crept into the temple 
worship, and priest and king vied with each other for 
power. 

In the time of Egypt’s decadence, we find that the 
temple, instead of a simple building, had grown to an 
immense system of buildings, vast avenues, arch after 
arch and court after court, flanked with rows of mas- 
sive stone sphinxes and decorated with ornate carv- 
ing, sculpture, and reliefs all painted in the vivid 
ocher reds and copper blues that the Egyptians loved. 
Kach succeeding ruler has added to the temple, in an 
effort to outshine all his predecessors. For many 
generations they preserved the convention of the 
eastern doorway, though the reason for its position 
had long since faded from their dogmas. But finally 
a king was balked in his plans by the banks of the 


BRONZE BEAUTY 349 


Nile. Doubtless there were many consultations be- 
tween the powers that were, but in the end they evi- 
dently decided that the direction did not really matter 
very much, and the new part of the temple bends at a 
sharp angle to the old. The priests had so far won in 
the struggle for supremacy that they made the king 
come to the temple for instructions from the gods. 
The whole temple was planned at this time for the 
effect of mystery. Deeper and deeper grew the twi- 
light as the king advanced through the now labyrin- 
thine corridors. Eventually he reached the innermost 
sanctum, and prostrated himself before the image of 
the god. Fvery artifice was used to make this moment 
impressive. Then the bronze figure stirred and moved 
clankingly toward him, a sign of divine approbation. 
It was huge and hideous, and, of course, hollow and 
jointed. It opened its mouth and instructed the king 
in his duty to the gods and the proper conduct 
of affairs of state. We need seek no more art in 
Kigypt. No more greatness could come from a people 
whose highest ideals were satisfied with this mum- 
mery. 

When we turn to Greek art, we find it developing by 
the aid of new methods in metal-working. Although 
we commonly think of statues of white marble when 
we think of Greek art, the Greeks got their training in 
sculpture through the medium of bronze. Their early 
work, like that of the Egyptians, was made in sections, 
and most of the statue was beaten out of sheet metal. 
The technical name of this method is repoussé., The 
copper is laid on a block of wax, asphalt, or similar 
resilient material, and the design is beaten in, in in- 


300 THE STORY OF COPPER 


tagho effect; then the sheet of metal is turned around 
and the background is hammered down, away from the 
figures which now appear in relief. Greek artists be- 
came marvelously proficient in work of this kind, beat- 
ing out the metal until it is very thin in the complex 
designs, with their delicate detail in high relief, with- 
out breaking through the metal. 

But the Greeks’ real statuary developed after they 
had passed the hammer and rivet stage, when they dis- 
covered an extremely ingenious method of casting 
hollow bronze statues over a core of clay, the method 
which is still used under the name a cire perdue. The 
figure was built up of the plastic clay and given its 
final outline. Then several coats of wax were applied, 
until the desired thickness was reached, and after the 
final coat the detail was put in and the statue finished. 
Then more clay was added until the whole figure was 
covered with a thick coat of it. Reinforcing-rods long 
enough to reach the inner core were then driven in, 
and the shapeless bundle was put into a furnace where 
the clay was baked hard and the wax melted. Holes 
had been left in a few places through which the wax 
could run out, and through them molten bronze was 
poured in after the baking. When the metal had had 
time to cool, the outer crust of clay was broken off, 
leaving the bronze casting in need only of a little 
smoothing and burnishing, and, perhaps, some inlay 
work of gold, silver, or jewels about the eyes, lips, and 
drapery. Statues made in this way possessed all the 
beauty and durability of the metal and at the same 
time gave the artist the freedom of working in a 
plastic material. The combination is ideal. 


BRONZE BEAUTY ool 


The early Greek sculptors preferred bronze for their 
statues. About the time of Phidias, marble seems to 
have come into favor; but that genius used bronze for 
his first statues, and there are many who believe that 
all his works were made in metal and that the marble 
ones that we have are only copies of lost bronze 
originals. 

Certainly their bronze work gave to the Greeks their 
ability to portray motion, for their methods of model- 
ing allowed the greatest freedom in the position of the 
figures without anxiety about their centers of gravity. 
Higypt, on the other hand, which began with stone 
figures, never got entirely away from the feeling of 
uneasiness lest the statue tip over. Many of their 
figures are noticeable for their perpendicular attitudes, 
whether sitting or standing, and those sculptors who 
dared put the feet a little distance apart usually left 
an uncut pillar at the back, giving the statue the 
stability of a three-point support. 

The Greeks believed in having things true to life. 
Their marble statues were painted as to flesh and 
drapery, and wings and hair were often gilded. There 
is a legend that their metallurgists were adept at mak- 
ing many kinds of bronzes, and that the color of the 
alloy was carefully chosen with regard to the subject 
of the statue. <A silvery metal was said to be employed 
in representing sea divinities, while for the sun- 
browned athletes the darkest bronze was used. 

It is impossible here to review the technical points 
of superiority of Greek art, but something of the 
spirit which made it possible must be noted. We left 
Egypt with its artistic impulses and its life saddled 


302 THE STORY OF COPPER 


with mysterious cults dedicated to perpetuating the 
ideas of the past. Parallels are sometimes drawn be- 
tween the Greek and the Egyptian polytheisms, but 
the Greeks were bound by no such backward-looking 
cults of mysticism and fear. Theirs was a joyful 
nature-worship, animistic, it is true, but poetically 
conceived. Crude as their beliefs seem to us to-day, 
they gave to those early people a freedom of thought 
. never before attained. This, combined with their in- 
herent feeling for beauty, flowered in those idealized 
figures of calm power and graceful strength which we 
still regard as among the most perfect works ever 
done by man, irrespective of time. When we compare 
them with their contemporary art in other countries 
we can only be amazed. 

So keen was the Greek love of the beautiful that not 
only were their temples and their palaces beautiful 
but their clay bowls, copper pots and lamps, furniture, 
household goods of every sort were made in beautifully 
proportioned shapes and charmingly decorated. Of 
course not every potter and coppersmith was an artist 
of the rank of Phidias or Praxiteles, even in the 
golden age of Greece, but the race did seem endowed 
with that fine appreciation of lovely things which we 
call good taste. The worst of their products still have 
many good points. They never offend. 

It is curious to see how the art movements of every 
people follow the same general curve. At first the 
artist must learn the principles of drawing and sculp- 
ture and acquire ease of manipulation of the stone, 
the metals, and the pigments that were at hand. 
Then, with the joy that comes with that power, a 


THE BRIDGE 


Etching on copper by Whistler, showing the delicacy of line possible in that 
style of work. With a minimum number of lines, the artist has given us the 
crowded waterfront, each figure in a characteristic attitude, the houses, the trees, 
the mountain in the far distance, and even the texture of the clouds. The reflec- 
tions in the stream are especially interesting. Each line of an etching is scratched 
in a copper plate with a hard stylus and then deepened with acid to hold the ink. 


‘= 


Photograph by L. C. Handy 


GRIEF 


Augustus Saint-Gaudens’s masterpiece, Rock Creek Cemetery, Washington. This 
is one of the finest bronzes, not alone of modern art, but of all time. 


BRONZE BEAUTY 303 


spontaneous explosion of vigorous and beautiful crea- 
tions appears. The decadence begins when the artists 
have tried their materials to their limits. Intricate 
technique supplants inspiration. The artists become 
more interested in how they do things than in what 
they are doing. Then criticism, comparing the results 
with those of earlier, more naive workers, turns the 
artists back to a sophisticated imitation of earlier 
methods, and the quality of the result improves for a 
time. But in a hundred years or so this flicker has 
died out, and art is dead until some new impulse in 
the national life wakes it to new being. 

Greece never reached the period of decadence. The 
country was but little past its prime when it fell before 
the Roman legionaries. Roman art, on the other 
hand, never had a beginning. It was not an outgrowth 
of the primitive Etruscan work that is found on the 
site of the early Roman state. Rather, the Romans, 
with their curious notion that they could buy brains, 
imported artists from Egypt and Greece, fed and 
clothed them, gave them the status of slaves, and 
ordered them to turn out so many statues a month. 
It is said that their systems of quantity production 
of art works would be a credit to manufacturers of 
machine parts to-day. Roman statuary found its high- 
est use in glorifying the bloody exploits of the 
country’s military heroes. The workmen were the 
best that the empire afforded—the pick of the world. 
The result was inevitable. Good likenesses were 
usually produced—only occasionally a good statue. 

Statues were, however, exceedingly fashionable dur- 
ing the period of the Roman Empire. Objets d’art 


304. THE STORY OF COPPER 


were collected by amateur connoisseurs even more as- 
siduously than during our own mid-Victorian era, and 
dozens, even hundreds, of statues of every quality 
adorned the Roman equivalent of the parlor what-not. 
In the ruins of one theater—not a large one, at that 
—were found three thousand bronze statues intended 
merely as incidental decoration. It is perhaps just 
as well that the early Christians piously set about de- 
stroying the relics of pagan Rome. Although we may 
have lost some fine things by it, we have assuredly 
been spared many things that were sins, if not against” 
religion, certainly against art. 

Bronze was always a favorite material with the 
Romans. Aside from its use in art works, it played 
an important part in religious ritual. Although iron 
had been known for hundreds of years it was looked 
down upon, and copper was considered the only proper 
metal for ceremonial use. The distinction was carried 
so far that a priest of Jupiter might shave his beard 
only with a bronze razor. It was decreed, too, by an- 
cient usage that ground for a new town must be broken 
by a plow whose plowshare was of bronze. 

When art again appears, it is under the influence of 
the Christian church. The Goths and the Vandals, 
upon embracing Christianity, imputed religious mo- 
tives to their lust for destruction and stripped Rome 
of her landmarks of paganism. Only those statues 
supposed to represent the converted emperor Con- 
stantine escaped. But, even while they destroyed the 
older civilization, the barbarian sculptors and metal- 
workers were learning principles of their art. In a 
few centuries we find new statues, with the motive- 


BRONZE BEAUTY 300 


power of a new religion behind their creation. The 
Gauls of Cesar’s time were clever metal-workers. 
They later learned from the Romans to build of stone, 
and from the Byzantine school to ornament with 
marble and mosaics; but bronze remained a favorite 
medium for statues, probably gaining in favor for that 
use from the fact that stone statues were associated 
with heathen idols. 

During the middle ages, painting and sculpture de- 
veloped as accessories to the building of the great 
cathedrals. Most of the people, even the kings and 
nobles, were unable to read and write. The decora- 
tions of the cathedrals were intended as a course in 
religious history and philosophy. Their inspiration 
was drawn from nature. Although they were planned 
by the priests and made under their direction, the 
handling of their subjects was not conventional, and 
the stories of the Old and New Testaments furnished 
lively scenes and ample opportunity for character por- 
trayal. Besides being used for statues, bronze was a 
favored material for doors, screens, reliefs, memorial 
tablets, and other church furniture, while copper in 
- other forms figures largely in the rich paintings, and 
in the famous colored glass of the windows. 

Cast objects at this period were made by the modern 
process instead of the a cire perdue, or ‘‘lost wax”? 
method of the ancients. The newer process has the ad- 
vantage that accidents caused by unfortunate circum- 
stances or a careless workman at the bronze founder’s 
do not destroy the artist’s original creation. The 
modern artist, after building a frame of iron bars and 
wooden scaffolding, covers it with clay which he can 


306 - THE STORY OF COPPER 


shape at will, and then makes a cast of the whole in 
plaster and from that a plaster model. Upon this 
model are placed the final finishing touches, before it 
is sent to the metal caster. The metal caster makes 
his mold from the plaster model. Of course, the molds 
made around the figure are in hundreds of separate 
small pieces, so that they can be removed without dan- 
ger of breaking any part. When the molds are ready 
the molten metal is poured through places where some 
of these pieces have been withdrawn. It fills the space 
between the mold and the inner core, for bronze statues 
are never solid. The metal is too precious to waste 
on any place which will not show. 

All through the middle ages, art was progressing. 
Materials were mastered, technique was standardized, 
composition was developed. The Renaissance was 
only the fulfilment of all that had been learned before. 
But with the Renaissance came a change in the mission 
of art. It soon began to appear outside the church. 
Wealthy families could afford things formerly pos- 
sessed only by the church. Their desire for beautiful 
paintings and statues gave a new impetus to art. But 
the greatest new influence in the world was the print- 
ing-press. Men no longer had to study the pictures 
in the cathedrals if they were curious about those who 
had lived before them. They began to go to books 
for such things. And, for the first time in the world, 
art was without a definite mission. It was set off by 
itself. It might assist other departments of learning, 
but it was not bound by them. It was set suddenly 
and completely free for the mere pursuit of beauty. 
The mechanical multiplication of the written word 


BRONZE BEAUTY 307 


took away art’s obligation of story-telling. The Ref- 
ormation threw art out of the church. The acrimoni- 
ous years that followed so fettered the minds of the 
religious disputants that the joy necessary to creative 
work was quite dead. Art in the churches soon de- 
generated to the distressing monotony which marks it 
to-day. 

We are accustomed to think of the Renaissance as 
a distant event. But if the love of art and science 
was reborn in the fifteenth and sixteenth centuries, it 
is still in a period of vigorous growth. Hindered from 
time to time by social upheavals and foreign wars, the 
intellect of the race goes on conquering the materials 
of which the world is made and the laws by which they 
can be put to the use of man. Is not this the first step 
toward their free use for the satisfaction of man’s in- 
herent need of beautiful surroundings? If the process 
seems slow, we must remember that even the flower- 
ing of the Greek genius required many hundred years 
-of preparation, and how much more complex a world 
modern science has opened up for us to conquer! 

When the archeologist of the year 4422 a.p. looks 
back at the art of our era his adverse criticisms may 
be: ‘‘It was a period of transition which, although 
producing many excellent things, followed rather too 
closely older masterpieces of painting and sculpture, 
whose technique had already reached perfection,’’ 
and ‘‘the art works seem to have been grouped to- 
gether in special buildings whose use, other than as 
mere museums, is unknown to us. This practice, if 
our assumptions concerning it are correct, must have 
deprived great numbers of people of the opportunity 


308 THE STORY OF COPPER 


to become acquainted with the works of their great 
artists. Lacking the training which they might have 
received through constant association with beautiful 
surroundings, it is doubtful whether the general level 
of taste among the less fortunate classes was very 
high.’’ 

The Egyptians built elaborate tombs; the Greeks 
made temples and statues to idealize their heroes; the 
Romans erected triumphal arches; the people of the 
middle ages built cathedrals. What will be our char- 
acteristic form of expression in art? It is as yet too 
early to know definitely. Art of the future may well 
have as its object the beautifying of our daily lives. 
The old order of magnificent public buildings sur- 
rounded by mean and filthy huts is beginning to seem 
incongruous to the world to-day. But, whatever its 
form, we may be sure that the art of to-morrow will be 
machine-made. | 

The fact that this sounds paradoxical is the result 
of an artistic tragedy—nothing less. When the me- 
chanical age first dawned, Art, who had always had to 
rely cn her two hands, forgot the potter’s wheel on 
which she made her lovely vases and the looms on 
which she wove her beautiful fabrics, and cried out that 
she never could learn to understand that horrid ma- 
chinery and that she would have nothing whatever to 
do withit. She tried to hide her unwillingness to learn 
something new with the statement that things made in 
great numbers all alike are incapable of beauty, but 
the facts are quite otherwise; for an archeologist can 
often place the origin of a bowl or a bronze celt quite 
accurately within a few years and a hundred miles, be- 


BRONZE BEAUTY 309 


cause its shape and decoration were the invariable rule 
at that place and time, and, at that place and time, 
such a shape and decoration represented a very high 
form of artistic feeling. No, the plain facts are that 
artists were afraid of the new fields. It was so much 
easier to go on painting and modeling as hundreds of 
others had done before, regardless of the fact that all 
the important principles of those methods had already 
been worked out. And so the manufacture of our fur- 
niture and clothing and building-trim and statues was 
largely left for a time to factory foremen who used a 
great new power without vision and visited some atro- 
cities of taste upon a helpless market. But the worst 
of their products have found their way to the junk- 
piles, and we can now see evidence of the tardy ap- 
pearance of the artist in the plant designing-rooms. 
In the future we may expect to see the artist take his 
place beside the engineer, the sanitarian, and the 
scientist as one of those who make the world a better 
place to live in. We may be sure that the beauty of 
copper and bronze will always make them favorites 
whether for utilitarian bowls and pans or for the por- 
trayal of the slender grace and rugged strength of 
human figures, just as they have always been. 

If the metals are fused more carefully and blended 
more exactly by the aid of electricity instead of char- 
coal; if the molten product is carried by automatic 
ears to the molds, instead of by sweating human 
bodies; if it is run into a thousand molds at a time 
instead of one; if the beauty of the finished object can 
be enjoyed by the humble, instead of the rich art pa- 
tron alone—who will be the loser, if the mold be de- 
signed by another Phidias? 


CHAPTER XVII 
COPPER’S FUTURE 


Old as the very hills themselves, man’s first metallic 
aide would seem to be in its old age. Yet in reality 
copper is still in the adolescence of its second youth. 
Before it hes the world eager for its help. It has 
been a leader in the mechanical revolution that the 
world has been experiencing, and it will continue to 
carry many of the burdens of the new era. 

The science of electricity has just begun to yield 
results of considerable magnitude. The vulgar mind 
has only begun to appreciate the possibilities of send- 
ing power along a copper wire as water is sent through 
a pipe. Every progressive country on earth is look- 
ing forward to getting on an electrical basis. While 
water plunges over falls wastefully, the far-seeing man 
does not like to use coal, which only the sunshine of 
countless ages could replace. He will demand that hy- 
draulic power be harnessed and driven through copper 
to his home and factory. Projects actually planned 
will require many millions of pounds of copper in the 
next few years. 

Though communication had the aid of electricity 
and copper before the electric dynamo and motor 
created and used copper-carried electric power, to- 
morrow will see new means of human intercourse. 


The telegraph allowed written messages to travel with 
360 


COPPER’S FUTURE 361 


electrical speed; the telephone throws the human voice 
across continents. Within a few years pictures and 
photographs will be sent from place to place with 
telegraphic speed; the next step will be actually to 
transmit the scenes themselves, and we shall see 
through copper stretched many hundreds of miles. 

Brass and bronze will continue to perform their 
service for many years, but to these copper alloys 
there will be added new partnerships that may be far 
superior for many uses. And it is probable that these 
new combinations will be designed before being built. 
With the X-ray spectrometer the metallurgist is learn- 
ing the secrets of metallic combinations. By laborious 
experiments he is mapping on alloy constitution dia- 
grams the properties of various alloys when their in- 
gredients vary in material and percentage. Soon it is 
expected that the rules of alloying and the resulting 
properties will be discovered with such precision that 
the metallurgist will be able to compete with the chem- 
ist and produce new, valuable, and synthetic alloys, 
having predetermined properties, just as the chemist 
makes new drugs, chemicals, and dyes. 

It is possible that the days when another Butte or 
Katanga can be discovered are passing, yet the pros- 
pector must be with us always in order that the world 
may continue to have an ample supply of red metal. 
But the prospector will be of the new era; he must not 
be visualized as a picturesque character, with his ‘‘out- 
fit?? and a few burros. More likely he will be found 
in a research laboratory. New mines in the future 
will be found but infrequently; new ways to mine 
known deposits and concentrate and smelt lean ore will 


362 THE STORY OF COPPER 


be eagerly sought and found. The prospector of to- 
morrow will play a game of hide-and-seek with Na- 
ture, but he will work in the mine, reduction plant, or 
refinery and not in totally unexplored country. 

In this world there is only a certain, limited amount 
of copper. All the people who come after us to live 
on this earth will have that quantity and no more. 
In fairness to our descendants we must use copper 
and all other natural resources intelligently and care- 
fully. 

Yet we have a very good reason for using all the 
copper we actually need and for doing so with a clear 
conscience. Unlike most metals, copper is not a rap: 
idly wasting asset. Copper in many cases loses but 
little of itself even during long service. There is, 
to be sure, some wastage; and in some cases, as when 
its salts are used for insecticides, none of the copper 
content can be reclaimed. Yet, years after its first 
mining, most copper can be remelted and utilized 
again in some other form. Millions of miles of cop- 
per wire now in use in power, telephone, and telegraph 
systems will add just as much comfort, pleasure, and 
efficiency to future generations as to the present. 

To restrain ourselves unduly in our present use of 
copper for fear of future shortage would also be dis- 
counting the continued ability of man to conquer the 
vital problems that will confront him. In the distant 
future it is possible that copper will not be so essentiai 
as it now is, because of the perfection of new aids to 
civilization. 

When copper’s low depreciation is contrasted with 


COPPER’S FUTURE 363 


iron’s expensive rusting, the picture is striking. 
Hivery year an amount of iron, said to equal one fourth 
of the annual production, reverts to its most contented 
form, rust. While the blast-furnace has been produc- 
ing four pounds of new iron, one pound has rusted 
away. Ina generation, if all iron production stopped, 
there would be little left to show that there ever was 
an iron age. Corrosion also means loss of coal, be- 
cause for every pound of iron produced about four 
pounds of this valuable basic fuel are required. This 
phase of the situation is more serious than the loss of 
the iron, since our coal supplies are more severely 
limited than our iron ore. Nearly twenty million tons 
of iron revert to red rust during each year. Iron is 
spent when it is used and its scrap value is often vir- 
tually nothing even if it misses its usual fate of rust- 
ing. 

To use copper, however, is to invest it. Since 1800 
there have been produced a little more than 27,000,000 
tons of copper. Much of this will continue in use for 
many years longer; a large part of it will be re-used. 
Suppose that only half of this quantity is reclaimable 
at ten cents a pound scrap value; it represents an in- 
vestment of about $3,035,000,000, which is increased at 
the rate of about $125,000,000 a year. No other com- 
mon metal can show such a balance-sheet. 

Some day in the future there will be an event com- 
parable in importance to the completion of the Atlantic 
eable or the driving of the last spike of a transcon- 
tinental railroad. It may be the throwing of many 
superpower electric systems into one continental unit 


364 THE STORY OF COPPER 


or the completion of a gigantic world net of electrical 
communication. How fittingly symbolic it would be 
if the switch on that occasion were fabricated from a 
copper ax, a relic of the days of the youth of civiliza- 
tion! 


READING REFERENCES ON COPPER 


Much information not contained in the preceding 
pages will be desired by those who wish detailed knowl- 
edge of certain phases of the history, nature, manu- 
facture, and use of copper. Further data on copper 
are to be found in more technical volumes. Often the 
subject that is dismissed with only a chapter or even 
a paragraph of this book will occupy the whole of 
some technical work. The object of this book is to in- 
troduce copper to the reader rather than to expose all 
the details of its character; it is hoped that the reader 
will be interested enough to search out the more tech- 
nical volumes and absorb what they contain about red 
metal. 


CHAPTER I 


For a realization of the way in which man arose 
through the ages and the part that the various factors 
in civilization played in his evolution, no better book 
ean be read than ‘‘The Outline of History’’ by H. G. 
Wells (Macmillan). The small amount of detailed in- 
formation on the use of copper and copper alloys in 
early time is scattered in several places. ‘‘Man and 
Metals,’’ by Walter Hough, curator of anthropology 


of the United States National Museum (Proceedings 
365 


366 THE STORY OF COPPER 


of the National Academy of Sciences, Vol. II, March, 
1916), is an interesting analysis of the connection be- 
tween man’s early use of metals and fire. Dr. Hough 
in the Proceedings of the United States National Mu- 
seum, Vol. LX, has also described a synoptic series of 
objects in the National Museum illustrating the history 
of inventions. In the development of the knife, ax, 
adz, hammer, saw, drill, piercing and stabbing weap- 
pons, cutting and thrusting weapons, and harpoon the 
material is stone, bone or wood, copper or bronze, and 
then iron and steel in virtually all cases. A summary 
of the use of copper and its alloys in early times, with 
analyses of ancient copper and alloys, is contained 
in the presidential address of Professor William Gow- 
land before the Institute of Metals, London, 1912, pub- 
lished in the ‘‘ Journal of the Institute of Metals,’’ Vol. 
VII. The state of metallurgical knowledge in the six- 
teenth century has been preserved for us in the first 
comprehensive text on mining and metals, ‘‘De Re 
Metallica,’’ by Georgius Agricola. From the first 
Latin edition of 1556, Herbert Clark Hoover and Lou 
Henry Hoover have made an English translation 
whose notes amply explain the text and summarize 
what is known of metallurgy up to Agricola’s time. 
This work was published for Mr. and Mrs. Hoover by 
the ‘‘ Mining Magazine,’’ London, 1912. Several of its 
interesting woodcuts are reproduced in the text of this 
book. Much information on the use of copper by the 
American Indians and the aborigines of Central and 
South America can be found in the reports of arche- 
ological work on the past history of America. Bul- 


READING REFERENCES 367 


letin 30 of the Bureau of American Ethnology, edited 
by Dr. J. Walter Fewkes of the Smithsonian Institu- 
tion, contains a brief summary of the Indians’ use 
of copper, with a bibliography. ‘‘Bronze in South 
America Before the Arrival of the Europeans,’’ by 
Adrien de Mortillet, in the Smithsonian report for 
1907, reports analyses of pre-Columbian metals, as 
does ‘‘Prehistoric Bronze in South America,’’ by 
Charles W. Mead, in Anthropological Papers of the 
American Museum of Natural History, Vol. XII, Part 
II, 1915. An account of the early use of copper and 
bronze is contained in ‘‘L’humanité prehistorique,’’ 
by Jacques de Morgan, published in Paris. ‘‘Prehis- 
toric Times,’’ by Sir John Lubbock (Lord Avebury), 
published by J. A. Hill & Co., contains information on 
the ancient use of copper and bronze. A guide to the 
antiquities of the bronze age in the British Museum 
was published by the museum in 1904, and collections 
of copper and bronze implements of early times can 
be found in virtually all the large museums. A series 
of articles, ‘‘An Illustrated History of Mining and 
Metallurgy,’’ by H. H. Manchester, were published in 
the ‘‘Hngineering and Mining Journal-Press’’ in the 
autumn of 1922 and have been reprinted in pamphlet 
form. They contain interesting information on the 
four periods: the Egyptian period, that of the Greeks 
and Romans, the Middle Ages in Europe, and in six- 
teenth-century America. An article by the same 
author in the same journal for May 19, 1923 (Vol. 115, 
No. 20) gives an interesting account of mining in 
Old Japan. 


368 THE STORY OF COPPER 


CHAPTER II 


Accounts of the mineralogy and geology of copper 
may be found in all of the ordinary texts on geology 
and mineralogy. A semi-technical review of the geol- 
ogy of copper may be found in such a book as ‘‘ Kico- 
nomic Geology,’’ by Heinrich Ries (John Wiley & 
Sons), or ‘‘General Economic Geology (A Text 
Book),’’ by William Harvey Emmons (McGraw-Hill 
Book Co.). More limited treatment can be found in 
‘‘Hingineering Geology,’’ by Heinrich Ries and Thomas 
L. Watson. ‘‘The Data of Geochemistry,’’ by F. W. 
Clarke, Bulletin 695, U. S. Geological Survey, is a com- 
prehensive work on the crust of the earth and includes 
a chapter on copper. For methods of identifying and 
testing the ores of copper and the minerals in whose 
composition copper plays a part, a book on mineralogy 
like ‘‘Klements of Mineralogy, Crystallography, and 
Blowpipe Analysis,’’ by Alfred J. Moses and Charles 
Lathrop Parsons (D. Van Nostrand Co.), should be 
consulted. The Bureau of Mines has also issued a 
pamphlet on the ‘‘Ores of Copper, Lead, Gold and Sil- 
ver,’’ by Charles H. Fulton, as Technical Paper 143 
(Government Printing Office, Washington). <A stand- 
ard work on the genesis of the parts of earth’s crust 
that are rich enough to be called ore is ‘‘ Mineral De- 
posits,’? by Waldemar Lindgren (McGraw-Hill Book 
Co.). This presents in one volume on coordinated 
summary and interpretation of the various theories 
and investigations of mineral deposits. Detailed de- 
scriptions of copper minerals and deposits may be 
found in the many geological reports that have been 


READING REFERENCES 369 


made on those portions of the world that contain cop- 
per. Experts of the United States Geological Survey 
have made many of these, and the reports of this bu- 
reau contain much of the public information on the 
mineralogy of copper. 


CHAPTER III 


From a geographical and quantitative standpoint, 
as well as geologically, technical information on cop- 
per is scattered in many books and reports. In ‘‘The 
Copper Mines of the World,’’ by Walter Harvey Weed 
(McGraw-Hill Book Co.), the copper-producing cen- 
ters are treated from a geological and mining point 
of view. This book provides a handbook on the copper 
resources of the world. A more recent digest of 
statistical and technical information relative to the 
production, consumption, and value of copper has been 
issued in 1922 by the Imperial Mineral Resources Bu- 
reau of the British Government. This publication en- 
titled, ‘‘The Mineral Industry of the British Empire 
and Foreign Countries: Copper,’’ covers particu- 
larly the war period for 19138 to 1919. In addition to 
its text, it contains a valuable bibliography of the tech- 
nical literature on copper since 1913, which includes 
references on occurrence, distribution, and mining, 
listed geographically, and also those on ore dressing, 
metallurgy, alloys, and uses. A summary of copper’s 
place in political and commercial affairs is contained 
in a chapter on copper by F. W. Paine in ‘‘ Political 


310 THE STORY OF COPPER 


and Commercial Geology and the World’s Mineral Re- 
sources,’’ edited by J. E. Spurr (McGraw-Hill Book 
Co.). A similar summary, though not so technical, 
written during the war instead of after, is the chapter 
by B.S. Butler in ‘‘The Strategy of Minerals,’’ edited 
by George Otis Smith (D. Appleton and Company). 
The distribution, production, and consumption of cop- 
per in all parts of the world and the United States are 
shown graphically in the valuable World Atlas of Com- 
mercial Geology, Part I, ‘‘Distribution of Mineral 
Production,’’ that is published by the United States 
Geological Survey. Information on the history and 
geology of the different mining centers must be sought 
in the periodical literature, Geological Survey reports, 
and literature issued by the various copper companies. 
‘“‘The Copper Mines of Lake Superior,’’ by T. A. 
Rickard (‘‘Engineering and Mining Journal’’), is a 
book covering the Michigan region. A review of 
Alaskan copper history and prospects is found in 
‘The Future of Alaskan Mining and the Alaskan Min- 
ing Industry in 1919,’’ by Alfred H. Brooks and G. C. 
Martin, Bulletin 714A of the United States Geological 
Survey. Other Geological Survey reports, such as 
Professional Paper 115, ‘‘The Copper Deposits of Ray 
and Miami, Arizona,’’ by Frederick Leslie Ransome, 
will be interesting to those who may wish to know more 
about a certain region. A monograph of the British 
Imperial Institute on ‘‘Copper Ores’’ by Robert Al- 
len which was published in 1923 (John Murray, Lon- 
don) gives a summary of copper production, largely 
from a British point of view; but its data on foreign 
deposits will prove of interest. 


READING REFERENCES 371 


CHAPTER IV 


Old as mining is, the lhterature on winning metals 
from the earth is constantly growing. Information on 
new copper mining methods and new mines is con- 
tained in such periodicals as the ‘‘Kingineering and 
Mining Journal-Press’’ or the proceedings of societies 
such as the American Institute of Mining and Metal- 
lurgical Engineers. Herbert Hoover, mining engineer 
and Secretary of Commerce, is the author of a stand- 
ard work on ‘‘Principles of Mining’’ (McGraw-Hill 
Book Co.). The various copper companies also have 
issued bulletins on mining, and the publications of the 
United States Bureau of Mines contain similar infor- 
mation. For reference, a handbook like ‘‘Mining En- 
gineers’ Handbook,’’ by Robert Peele (John Wiley & 
Sons), is useful. In ‘‘The Cost of Mining,’’ by J. R. 
Finlay (McGraw-Hill Book Co.), data are given on 
the financial side of mining. 


CHAPTER V 


The experiences that copper has on its journey from 
mine to metal are the subjects of many books on metal- 
lurgy. Most extensive of these is ‘‘Metallurgy of 
Copper,’’ by H. O. Hofman (McGraw-Hill Book Co.), 
which gives copious references to detailed reports and 
studies on all the technical phases of copper’s reclama- 
tion. A more recent book, but one that treats the 
subject less fully, is ‘‘The Metallurgy of Common 
Metals,’’ by Leonard 8. Austin (John Wiley & Sons), 


372 THE STORY OF COPPER 


which also includes sections on general metallurgy and 
common metals. Hofman’s general book on metal- 
lurgy might also be used for reference. A connected 
outline of the processes employed in the production 
of copper is contained in a small English book, ‘‘Cop- 
per from the Ore to the Metal,’’ by Hugh K. Picard 
(Isaac Pitman & Sons, London). Other books that 
may be consulted on the metallurgy of copper in its 
various phases are: ‘‘The Principles of Copper 
Smelting,’’ by E. D. Peters (McGraw-Hill Book Co.) ; 
‘‘The Hydrometallurgy of Copper,’’ by William E. 
Greenwalt (McGraw-Hill Book Co.) ; ‘‘Copper Refin- 
ing,’’ by Lawrence Addicks (McGraw-Hill Book Co.). 
The Anaconda Copper Mining Company has issued a 
pamphlet, ‘‘Copper from Mine to Finished Product,’’ 
which explains the processes at their various reduc- 
tion and refining plants. ‘‘The Smelting of Copper 
Ores in the Electric Furnace,’’ by Dorsey A. Lyon and 
Robert M. Keeney, is Bulletin 81 of the United States 
Bureau of Mines, and other of the publications and 
current investigations of the Bureau of Mines touch 
on the metallurgy of copper. The magazines, ‘‘Chem- 
ical and Metallurgical Engineering’’ (New York), 
‘‘Hingineering and Mining Journal-Press’’ (New 
York), **The Metal Industry’? (New York), ‘‘The 
Brass World’? (New York), ‘‘Mining Magazine’’ 
(London), and ‘‘Mining Journal’’ (London), and the 
transactions of the American Institute of Mining and 
Metallurgical Engineers, the Institution of Mining 
and Metallurgy, the British Institute of Metals and the 
American Electro-Chemical Society contain accounts 
of current advances in metallurgy. The chapter on 


READING REFERENCES 373 


‘‘Copper’’ in the ‘‘Mineral Resources of the United 
States, Part I, Metals,’’ issued annually by the United 
States Geological Survey, contains a summary of the 
production and consumption of copper year by year. 
‘The Mines Handbook,”’ an enlargement of the ‘‘Cop- 
per Handbook,’’ by Walter Harvey Weed, is an an- 
nual volume that reviews the copper industry from a 
more commercial standpoint. Its most important fea- 
ture is a list of mining companies. Statistics on pro- 
duction of copper month by month are contained in 
the Survey of Current Business issued by the Depart- 
ment of Commerce. An analysis of the cost of cop- 
per is contained in ‘‘Costs of American Copper Pro- 
duction, 1909-1920, Inclusive,’’ by H. A. C. Jenison in 
the ‘‘Hngineering and Mining Journal,’’ Vol. CXIII, 
No. 11, March 18, 1922. A valuable summary of ‘‘The 
Marketing of Copper’’ is published by Edward H. 
Robie in the ‘‘ Engineering and Mining Journal-Press’’ 
for April 23, 1923. Those interested in copper share 
statistics may refer to a sheet compiled by E. N. Skin- 
ner, New York mining engineer, which annually tabu- 
lates data on various copper companies from a finan- 
cial standpoint. Other useful statistical books are 
‘‘The Mineral Industry.’’ (McGraw-Hill Book Co.) 
and ‘‘The Yearbook of the American Bureau of Metal 
Statistics.’ 


CHAPTER VI 


The cold, solid figures that represent the physical 
and chemical properties of the metal can be found 


ol4 THE STORY OF COPPER 


in the ‘‘Smithsonian Physical Tables, Seventh Revised 
Hdition,’’ published by the Smithsonian Institution. 
The mining, metallurgical, chemical, and mechanical 
engineering handbooks may also be consulted for such 
data. For further information on the close study of 
metals, the two volumes on ‘‘Metallography’’ by 
Samuel L. Hoyt (McGraw-Hill Book Co.) are recom- 
mended. This work treats of alloys as well as pure 
metals. The Bureau of Standards has also issued a 
number of valuable publications on copper. Bureau 
of Standards Circular 72, ‘‘Copper,’’ covers metal- 
lography, both chemical and physical properties, and 
technology, and includes an extensive bibliography. 
Bureau of Standards Circular 113, ‘‘Structure and Re- 
lated Properties of Metals,’’ gives a general and il- 
luminating review of the methods for revealing the 
structure of metals and the application of microscopy 
of metals. ‘‘Metallographic Etching Reagents for 
Copper’’ is the subject of Bureau of Standards Scien- 
tific Paper 399, by Henry 8S. Rawdon and Marjorie G. 
Lorentz. Chemical and electrolytic methods of analyz- 
ing copper and its ores are adequately covered in ‘‘' The 
Analysis of Copper,’’ by George L. Heath (McGraw- 
Hill Book Co.). The relatively new methods of 
spectographic analysis are treated in Bureau of Stand- 
ards Scientific Paper 444, ‘‘Practical Spectrographic 
Analysis,’’ by W. F. Meggers. <A short paper by W. 
H. Bassett and C. H. Davis, ‘‘Spectrum Analysis in 
an Industrial Laboratory,’’ issued with ‘‘Mining and 
Metallurgy,’’ February, 1922, as a part of the Transac- 
tions of the American Institute of Mining and Metal-_ 
lurgical Engineers, is also interesting. For discus- 


READING REFERENCES 370 


sions of some of the more recent ideas about the states 
and conditions of metals, recent magazine articles 
should be consulted. Jerome Alexander has a series 
of four articles on ‘‘Colloidal State in Metals and Al- 
loys,’’ in ‘‘Chemical and Metallurgical Engineering,’’ 
Vol. XXVIJ, January 11, January 18, January 25, and 
February 1, 1922. Other articles in the same mag- 
azine are: ‘‘Grain Growth and Recrystallization in 
Metals,’’ a series of three articles by Zay Jeffries and 
R. 8. Archer, February 22, March 1, and March 8, 
1922; ‘‘The Amorphous Metal Hypothesis,’’ by the 
same authors, October 12, 1921; and ‘‘A Discussion of 
the Slip Interference Theory of Hardening,’’ by Paul 
D. Merica, May 10, 1922. For an account of the meth- 
ods used in X-ray examination of crystals the reader 
should consult ‘‘Studies of Crystal Structure with X- 
rays,’’ by Edgar C. Bain, in ‘‘Chemical and Metal- 
lurgical Engineering’’ for October 5, 1921. A syn- 
opsis of Dr. Walter Rosenhain’s work on ‘‘ Hardness 
and Hardening’’ may be found in ‘‘Chemical and 
Metallurgical Engineering’’ for May 21, 1923. Speci- 
fications covering the tests to be made and the require- 
ments to be filled by copper and its alloys when used in 
various ways are given in the book of standards is- 
sued triennially by the American Society for Testing 
Materials. 


CHAPTER VII 


For a more detailed look inside the copper atom, 
the reader is advised to follow John Mills in his work, 


316 THE STORY OF COPPER 


‘‘Within the Atom’’ (D. Van Nostrand Co.). Though 
this is somewhat technical it is an adequate presenta- 
tion of our knowledge of the sub-molecular world. 
The original presentation of Irving Langmuir’s hy- 
potheses on ‘‘The Arrangement of Electrons in Atoms 
and Molecules’’ is contained in his article under that 
title in the ‘‘ Journal of the American Chemical Soci- 
ety,’’ June, 1919, Vol. XLI, and, though this is not 
very casy reading, it is not too technical for the lay- 
man. A very interesting account of how electrons and 
alpha particles are seen and photographed is contained 
in Sir Ernest Rutherford’s article, ‘‘Constitution of 
Matter,’’ in the Smithsonian Institution Annual Re- 
port for 1915. ‘‘The New Knowledge,’’ by Robert 
Kennedy Dunean (Harper & Brothers), is a little old 
now, but it is good as far as it goes. ‘‘The Structure 
of the Atom,’’ by Professor N. Bohr, published as a 
supplement to ‘‘Nature’’ (London), July 7, 1923, ex- 
plains the newest interpretation of the chemist’s atom 
as a solar system, as it is seen by the physicist. 


CHAPTER VIII 


The partnerships in which copper becomes involved 
are so intimately related to its inside story that the 
references given in connection with Chapter VI should 
also be considered applicable to this chapter. For in- 
formation on alloys of copper and aluminum, Bureau 
of Standards Circular No. 76, ‘‘Aluminum and its 
Light Alloys,’’ should be consulted, and copper-nickel 
alloys are explained in Bureau of Standards Cireular 


READING REFERENCES ol 


No. 100, ‘‘Nickel.’? The list of alloys referred to in 
Chapter VIII was compiled by Professor William 
Campbell of Columbia University for Committee B-2 
of the American Society for Testing Materials and ap- 
pears on pages 213-242 of their proceedings for 1922, 
Part 1. A practical volume on alloys prepared by an 
expert on alloying and casting metals is ‘‘Metals and 
Their Alloys,’’ by Charles Vickers (Henry Carey 
Baird & Co.). 


CHAPTER IX 


Much of the best information on the manufacture 
of copper and its alloys is contained in advertising 
literature issued by the copper and brass companies. 
The Anaconda booklet referred to previously contains 
a description of copper wire rolling, and ‘‘Seven Cen- 
turies of Brass Making,’’ a booklet issued by the 
Bridgeport Brass Company, Bridgeport, Connecticut, 
gives a brief history of the ancient art of brass mak- 
ing as well as the more modern processes. Circular 
No. 52 of the Bureau of Standards tells of the ‘‘ Regula- 
tion of Electrotyping Solutions,’’ and the Transactions 
of the Faraday Society, Vol. XVI, Part III, July 1, 
1921, contains a review of papers on electro-deposition 
and electroplating. Reference may also be made to 
‘‘Foundry Practice,’’ by R. H. Palmer (John Wiley 
& Sons), and ‘‘Hlectro-Deposition of Metals,’’ by 
George Langbein and William T. Brannt (McGraw- 
Hill Book Co.). Those who wish to try their own 
hand at making copper products should consult ‘‘Cop- 


318 THE STORY OF COPPER 


per Work: A Text Book,’’ by A. F. Rose (The Davis 
Press, Worcester, Massachusetts). 


CHAPTER X 


So fundamental is copper to the existence of elec- 
tricity that complete reference to books telling of their 
cooperation would be impossible. Data on copper wire 
and the electrical properties of copper may be found 
in electrical engineering handbooks and tables. The 
current literature, such as the periodicals, ‘‘ Electrical 
World” and ‘‘Electric Railway Journal,’’ necessarily 
contain many references to the electrical uses of cop- 
per. ‘Telephone Service,’’ Bureau of Standards Cir- 
cular No. 112, explains in much detail the way in which 
telephones and their complex systems form a part of 
our every-day life. Another Bureau of Standards 
publication, Letter-Circular 68, ‘‘The Common Uses of 
Electricity,’’ gives an idea of the universal use of 
electricity in the household. Of the many books on 
radio that have been published in the last few years, 
‘‘Letters of a Radio-Engineer to His Son,’’ by John 
Mills (Harcourt, Brace, and Company), will probably 
best explain to the determined reader why and how 
radio apparatus, made largely of copper, does its work. 
Lightning-rods are discussed in a chapter of ‘‘Agri- 
cultural Meteorology,’’ by J. Warren Smith (Mac- 
millan). 


CHAPTERS XI, XII, XIII 


The uses to which copper has been placed are so 


READING REFERENCES 319 


common and varied that references are seldom isolated 
and are largely scattered throughout the literature. 
One booklet, ‘‘Consumption of Copper and its Varied 
Uses,’’ by H. D. Hawkes (published by Cameron, 
Michel and Co., New York), contains a large amount 
of data, much of it statistical in nature, on the various 
tasks to which copper has been put by man. The Cop- 
per and Brass Research Association, an organization 
of producers and fabricators of copper and copper 
alloys, located at 25 Broadway, New York City, issues 
a periodical bulletin devoted to the uses of copper. 
The advertising literature of the various copper and 
brass companies also contain much data on the use of 
red metal and its alloys. Publications of the director 
of the mint tell more about the making of our copper 
money. 


CHAPTER XIV 


Like information on the use of copper, data on 
its compounds and their uses are scattered through- 
out the vast mass of literature describing the processes 
in which compounds of copper take part. Chemical 
texts, dictionaries, or handbooks may be consulted for 
detailed information concerning copper’s compounds. 


CHAPTER XV 


War utilizes all the industries of peace and forces 
the creation of many additional copper-consuming ac- 


380 THE STORY OF COPPER 


tivities. How war material was produced in America 
during the World War is told in ‘‘America’s Muni- 
tions, 1917-18,’’ the report of Benedict Crowell, As- 
sistant Secretary of War and director of munitions 
(Government Printing Office, Washington). Incident- 
ally this volume tells of the modern war use of copper. 


CHAPTER XVI 


A vivid description of the life of ancient Egypt is 
contained in ‘‘Manual of Egyptian Archeology,’’ by 
Sir G. Maspero, translated by Agnes 8. Johns. ‘‘The 
Story of Art throughout the Ages,’’ by 8S. Reinach, 
translated by Florence Simmonds, is an illustrated, 
condensed history of sculpture and painting. Its ac- 
count of the art works of Babylonian, Hittite, and 
other early peoples is especially complete. Covering 
the latter, better known periods in the history of art 
there is a great variety of books of history and 
criticism. 


INDEX 


Africa, 17 

Age of copper deposits, 50 
Agricola, 20 

Airplanes, 295 

Alaska, deposits, 75 

Alloy, first, 11 

Alloy, manufacture, 228 
Alloys, 186 

Alloys, aluminum, 196 

Alloys, antiquity, 208 

Alloys, nickel, 208 

Aluminum, 186, 247 
Aluminum-copper alloys, 196 
America, first copper mining in, 27 
American copper deposits, 65 
Amorphous metal theory, 158 
Amygdaloid copper, 47 
Anaconda reduction works, 101 
“Ankh,” 24 

Annealing, 162, 220 
Antimony, 37 

Archeology of copper, 9 
Arizona copper production, 67, 69 


Armor, 333 
Arsenic, 37 
Art, 341 


Artillery shell cases, 328 
Assaying, 150 
Atacamite, 40 

Atom structure, 175 
Atomic weights, 175 
Australia, copper deposits, 81 
Automobiles, 296 

Aztees, 12 

Azurite, 39, 316, 305 


Balance-sheet of copper, 363 
Ball mills, 105 

Beilby, George T., 158 

Bell metal, 202, 205 

Bells, 302 

Bingham, Utah, 74 

Bisbee, geology, 70 


Blast furnace, 111, 117 

Bornite, 36 

Brass, 14, 186, 228 

Brass casting shop, 231 

Brass, constitution diagram, 187 
Brass industry, history, 229 
Brass, manufacture, 213 

Brass, photomicrographs, 192 
Brasses, 200 

Brochantite, 40 

Bronze, 186, 228 

Bronze, constitution diagram, 199 
Bronze, in art, 341 

Bronze, invention, 11 

Bronze, machinery, 206 

Bronze, oldest piece, 19 

Butte, 46 

Butte, history, 67 


Calamine, 15, 229 
Calcine, 112 
Calico-printing, 311 
California deposits, 76 
Calumet & Hecla, 47 
Canada, copper production, 78 
“Carnegie”, 294 
Cartridge, army rifle, 325 
Cassiterite, 11 
Casting, 7, 226, 355 
Caving, 91 
Cementation, 127 
Ceramics, 307 
Chaleanthite, 40 
Chaleocite, 35 
Chalcopyrite, 36 
Chemical reagents, 318 
Chemistry, 169 
Chile Copper Company, 79 
Chile, copper deposits, 78 
China, 20 
China, copper deposits, 82 
Christian art, 354 
Chrysocolla, 39 

381 


382 


Chuquicamata, 75, 79, 131 

Clark, Senator W. A., 68 

Clifton-Morenci, 70 

Clocks, 299 

Coins, 284 

Coins, composition, 205 

Concentration of copper, 84, 100 

Conductivity, electrical, 162, 246 

Constitution diagrams, alloys, 187 

Consumption, copper, 215, 242 

Converter, 121 

Copper, abundance, 33 

Copper alloys, 186, 201 

Copper alluvial, 9 

Copper-aluminum, 
diagram, 196 

Copper and ceramics, 307 

Copper archeology, 9 

Copper, casting, 226 

Copper, chemical analysis, 149 

Copper, commercial shapes, 135 

Copper companies, 138 

Copper compounds, 303 

Copper concentration, 100 

Copper consumption, 215, 242 

Copper, cost, 140 

Copper crystal, size, 161 

Copper, crystal structure, 153, 155 

Copper, discovery, 3 

Copper, distribition of use, 214 

Copper, durability, 272 

Copper, earliest find, 17 

Copper, electrical conductivity, 
162, 246 

Copper, expense of using, 271 

Copper, for permanence, 267 

Copper, genesis, 32 

Copper, hardening, 164 

Copper, heritage, 53 

Copper, in ancient warfare, 334 

Copper, in building, 261 

Copper, in coins, 205, 284 

Copper, in dyeing, 312 

Copper, in finance, 284 

Copper in gold, 211 

Copper in insecticides, 314 

Copper, in medicine, 313 

Copper in the home, 277 

Copper in war, 322 

Copper industry, history, 63 

Copper, manufacture, 213 

Copper, marine use, 292 


constitution 


INDEX 


Copper, metallurgy, 100 

Copper, native, 34 

Copper-nickel alloy, 325 

Copper-nickel constitution 
gram, 197 

Copper, origin of name, 22 

Copper, photomicrographs, 153 

Copper, plating, 236 

Copper, precipitation by iron, 127 

Copper, production, 53 

Copper, production in U. S., 64 

Copper, properties, 145 

Copper, purity, 135 

Copper Queen Mine, 70 

Copper, secret signs, 51 

Copper, sheet, 222 

Copper, statistics, 139 

Copper sulphate, 17, 40, 315, 321 

Copper tarnish, 241 

Copper tests, 51 

Copper tubing, 222 

Copper valency, 184 

Copper’s future, 360 

Corrosion, 166 

Cost, copper, 140 

Cottrell precipitators, 124 

Covellite, 35 

Cro-Magnon paintings, 304, 343 

Cuprite, 38 

Cuprous oxide, 163 


dia- 


Daly, Marcus, 68 
Deoxidizers, casting, 227 
Deposits, sedimentary, 48 
Dioscorides, 15 

Discovery of copper, 3 
Drilling, 86 

Ducktown, Tennessee, 76 
Ductility, 161 
Durability, copper, 272 


_ Early drawings, 343 


Egypt, 18 

Egyptian art, 344 

Electric furnace, 234 

Electric street railway, 254 
Electrical expansion, 250 
Electricity, 244 
Electrodeposition, 236, 298, 318 
Electrolytic refining, 132 
Electrons, 177 

Electroplating, 236 


Elements, chemical, 169 
Ely, Nevada, 76 

Enargite, 37 

Engraving, 280 

Etching, 151 

Etching, art, 290 

Europe, copper deposits, 81 
Extrusion process, 221 


Famatinite, 40 

Filters, 110 

Fireworks, 320 
Flotation, 107 
Founders’ hoards, 12, 25 
Foundry, 231 

Future, 360 


Gangue, 41 

Gems, 315 

German need for copper, 331 
Glance, 35 

Glauber, 313 

Globe-Miami, 70 

Gold, 9 

Gold, in copper, 211 

Gossan, 49 

Gowland, William, 12 
Grand Central Terminal, 264 
Greek art, 349 


Hair dye, 321 

Hardening copper, 164 
Hardness, 158 

Hardness, scale of, 316 
Hardware, 269, 301 
Helium, 177 

Heritage of copper, 53 
History of copper’s use, 30 
Hoover, Herbert, 20 

Hot springs, 43 

Houghton, Douglas, 72 
Hydrogen, 32 
Hydro-metallurgy, 103, 126 


India, 21 

Indian ornaments, 14 
Indian paint, 305 
Indians, 27 
Insecticides, 314 
Inside story, 144 
Iron Age, 216 

Iron, priority of, 25 


INDEX 


Japan, copper deposits, 80 
Jerome, Arizona, 71 

Jigs, 103 

Junior partners, 186 
Junk, 83 


Katanga, 75, 82 
Keweenaw peninsula, 7] 
Key to Civilization, 3 


“Lake” copper, 125 
Lake Superior, 27, 47 


Lake Superior deposits, geology, 
73 


Lake Superior, history, 71 
Langmuir, Irving, 177 
Leaching, 126, 129 

Lead in alloys, 204 
Level, mine, 88 

Lewis, G. N., 177 
Lightning-rods, 258 


Magma, 43 

Malachite, 38, 304, 316 
Manganese bronze, 203 
Matte, 116, 118 

Medals, 339 

Memorials, 337 
Mesopotamia, 17 
Metallic servant, 244 
Metallurgy, 103, 111, 126 
Metallurgy, beginnings, 10 
Metamorphism, contact, 45 
Mexico, copper mines, 77 
Microscopy, 151 

Mine, description, 86 
Minerals, 34 

Minerals, production, 40 
Mines, air, 94 

Mines, depth, 96 

Mines, fire, 92 

Mines, open cut, 96 
Mines, transportation, 91 
Mines, ventilation, 94 
Mines, water, 94 

Mining, 84 
Morenci-Metealf, 71 
Muntz metal, 202 


Native copper, 47 | 
Native copper metallurgy, 125 
Naugatuck Valley, 230 


383 


384 INDEX 


Nevada deposits, 76 Secondary copper, 82 

New Mexico deposits, 77 Shaft, mine, 87 

Nickel, 186 Sheet copper, 222 

Nickel alloys, 208 Sheet metal work, 267 

Nickel-copper alloys, 197 Ships, 292 

Nickel plating, 238 Show windows, 275 
“Shu-King” manuscripts, 8, 20 

Ore, crushing, 101 Sinai, 19 

Ore, formation, 44 Slag, 116, 122 

Ore, genealogy, 42 Smelters, location, 137 

Ore, geology, 42 Smelting, 111, 115 

Ore reserves, 58, 60 Spain, copper deposits, 80 

Ore richness, 85 Spectroscopy, 150 

Oxygen, 38 Speculum metal, 205 
Spelter, 229 

Paris green, 315 Sphalerite, 42 

Pariedie Table, 180 Statistics, copper, 139 

Permanence in building, 267 Statues, 338 

Peru copper deposits, 79 Stope, mine, 88 

Piercing process, 222 Sudbury deposits, 78 

Piements, 303 Sudbury, Ontario, 45 

Pins, 299 Sulphur, 35 

Plumbing, 268 Super-power system, 251 

Porphyry mines, 59 

Pottery, 306 Tamarack, 47 

Printing, 280 Telephones, 256 

Production by states, 63 Temples, copper in, 261 

Proving copper deposits, 86 Tenorite, 40 

Pryce, William, 8 Tetrahedrite, 37 

Pyrite, 36, 41 Textile dyeing, 311 

Pyritic smelting, 118 Thomson, Elihu, 225 

Pyro-metallurgy, 111 Tin, 11, 19, 199 
Tobin bronze, 203 

Radio, 257, 329 Transmission lines, copper, 247 

Railroad electrification, 252 eee pe aan 

Railroads, 297 ubing, 222 

Reading references, 365 

RoAnerion location, 136 Utah Copper Company, 75 

Refining, 130 Utah deposits, 74 

Renaissance, 356 : . 

Replacement, 45 Vein mines, 60 

Reserves of copper, 61 Veins, 45 

Reverberatory furnaces, 117 Venus, 23 

Rio Tinto, 80, 127 Vitriol, blue, 17, 40, 315, 321 

Roasting, 112 Volcanic vapors, 43 

Rolling mill, 219 + 

Roman art, 353 “Walrus and the Carpenter”, 174 

Roofing, 273 War, 322 

Rosenhain, Walter, 159 Washington Monument, 259 
Waterbury, Connecticut, 230 

Scales, 300 Weights, 300 


Screens, 269 | Welding, electric, 224 


INDEX 389 


Wire drawing, 219 X-ray spectroscopy, 159 
Wire, manufacture, 218 

Winzes, mine, 89 Zine, 15, 187, 229 
Work of the world, 284 


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